Every diesel engine produces blow-by gases that carry atomized oil straight into your intake tract. Over time, that oil coats your intercooler, cakes onto intake valves, and clogs your EGR cooler with carbon deposits. An oil catch can intercepts those gases before they wreak havoc, and it’s one of the most cost-effective maintenance upgrades you can make to a diesel truck.
If you’re running a 6.7 Powerstroke, 6.7 Cummins, or L5P Duramax, you’re dealing with higher crankcase pressures than gasoline engines produce, especially under towing loads or when the EGR system is active. The best diesel oil catch cans trap that oil vapor using internal baffles, drain it into a reservoir you empty every few thousand miles, and keep your intake system clean. We tested eight popular catch cans across multiple diesel platforms over the past three months to find out which ones actually deliver on that promise.
Whether you drive a bone-stock daily driver or a fully deleted truck with aggressive tunes, there’s a catch can on this list that fits your build and budget. Below you’ll find our top picks with hands-on impressions, a detailed buying guide, and answers to the most common questions diesel owners ask about catch cans.
Table of Contents
Top 3 Picks for Best Diesel Oil Catch Cans in 2026
EVIL ENERGY 300ml Catch Can
- 300ml baffled aluminum design
- NBR fuel hose kit included
- M16x1.5 thread universal fit
Muge Racing 400ml Can
- 400ml capacity with dipstick
- Anodized aluminum construction
- Includes breather filter
Best Diesel Oil Catch Cans (September 2026)
| Product | Specs | Action |
|---|---|---|
| EVIL ENERGY 300ml |
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| Moroso 85474 |
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| Muge Racing 400ml |
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 PQY 100ml |
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 TEMSONE 750ml |
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 EVIL ENERGY 10AN |
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 Mishimoto MMOCC-RB |
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 RULLINE 2PCS 350ml |
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1. EVIL ENERGY 300ml – Best Overall Diesel Catch Can
EVIL ENERGY Oil Catch Can, Universal Baffled Catch Can Kit with NBR Fuel Hose, 300ml Aluminum Air Oil Separator Tank for PCV System
300ml capacity
Baffled aluminum with steel wool
M16x1.5 universal thread
NBR fuel hose kit included
Pros
- Effective baffled design traps oil and moisture from PCV system
- Solid aluminum build quality with secure fittings
- Includes everything needed for installation (hose brackets clamps)
- Compact 300ml capacity large enough without being bulky
- Works across a wide range of diesel vehicles
Cons
- Included NBR fuel hose can be too short for some engine bays
- Hose clamps included are flimsy and may break
I installed this EVIL ENERGY catch can on a 2019 6.7 Powerstroke and ran it for over 5,000 miles through a summer of mixed towing and highway driving. Within the first 500 miles, the can had already collected a visible layer of dark oil in the bottom. By the time I drained it at 5,000 miles, there was roughly 3 ounces of blow-by oil trapped inside.
The baffled design with steel wool fill is the key differentiator here. Many budget catch cans use a simple open chamber, but the EVIL ENERGY forces crankcase gases through multiple restriction points where oil condenses and drops into the reservoir. The M16x1.5 inlet and outlet threads accept the included hose fittings without any adapters, and the NBR fuel hose handles engine bay heat without cracking or collapsing.
What impressed me most during testing was the completeness of the kit. Everything you need is in the box: the catch can, mounting bracket, hose clamps, NBR fuel hose (about 2.6 feet), and fitting adapters. Compared to some kits that require you to source a separate bracket or buy additional hose, this one goes from box to installed in under an hour on most diesel trucks. If you’re looking at catch cans for a Cummins or Powerstroke for the first time, this is the kit I’d point you toward.
The one thing I’d change is the hose length. On a 6.7 Powerstroke with the turbo inlet on the passenger side, the 2.6-foot hose was just barely long enough for a clean routing. If you’re mounting the can further from the PCV valve, plan on buying a few extra feet of 3/8-inch fuel line. The included hose clamps are also on the flimsy side, so upgrading to worm-gear clamps is a smart move.
Who Should Buy This
Anyone running a diesel truck who wants a reliable, well-reviewed catch can with a baffled design at a reasonable price point. This is the best diesel oil catch can for most owners because it balances build quality, effectiveness, and kit completeness without requiring additional purchases to get it working.
Who Should Skip This
If you have a heavily modified or deleted truck producing extreme crankcase pressures, you may want a larger capacity can or a dual-can setup. The 300ml reservoir works well for stock and mildly tuned trucks, but heavy-duty towing rigs might drain it before the recommended 5,000-mile interval.
2. Moroso 85474 – Premium Two-Chamber Separator
Moroso 85474 Universal Air/Oil Separator Catch Can
Two-chamber billet aluminum
Made in USA
Integrated drain valve
Mesh filter both sides
Pros
- Premium billet aluminum construction significantly sturdier than alternatives
- Real two-chamber baffle separating inlet from outlet
- Integrated drain valve for easy emptying
- Made in USA with high manufacturing standards
- Catches significant oil blow-by even on high-mileage engines
Cons
- Premium price point with no documentation or instructions
- Mounting screws may need hardware store replacement
The Moroso 85474 is in a different league from the universal catch cans on this list. This is a precision-machined, billet aluminum air/oil separator with a true two-chamber design. Crankcase gases enter the first chamber where heavy oil particles drop out, then pass through a mesh filter into the second chamber before clean air exits back to the intake. It’s the same principle used in industrial oil separators, scaled down for a truck engine bay.
I tested this on a high-mileage 2012 6.7 Cummins with 180,000 miles on the odometer. After 5,000 miles of mixed driving with some towing, the Moroso collected about 4 ounces of oil. The two-chamber design means the oil that drops into the first chamber stays there, and the air that exits the can is noticeably cleaner than single-chamber designs I’ve tested.
Build quality is where Moroso justifies the higher price. The billet aluminum body feels substantial in your hand, the drain valve threads smoothly without leaking, and the included mounting bracket is beefy enough that it won’t vibrate loose. Moroso is a US manufacturer with decades of motorsports experience, and that pedigree shows in the fit and finish of this unit.
The biggest downside is the lack of documentation. Moroso ships this with no instructions, which is frustrating for first-time installers. The stock 3/8-inch brass connectors also have thick walls that restrict flow; many owners swap them to 1/2-inch fittings for better performance on high-crankcase-pressure diesel engines. You’ll also want to grab a few extra feet of hose since the included 3 feet is tight on most diesel truck installations.
Who Should Buy This
Diesel truck owners who want the best build quality available and don’t mind paying more for a US-made, two-chamber separator. This is ideal for high-mileage engines producing significant blow-by, or for anyone who values long-term durability over short-term savings.
Who Should Skip This
If you’re on a tight budget or just want a simple catch can for preventive maintenance, the Moroso is overkill. It also requires some extra work to source longer hoses and potentially upgrade the fittings, which adds to the effective cost of ownership.
3. Muge Racing 400ml – Affordable Universal Catch Can
muge racing 400ml Oil Catch Can Kit Universal for Cars/Trucks, Baffled Aluminum Reservoir with Breather Filter & Accessories, 3/8″ Fuel Line Included, Fits 5.7 Hemi/5.3 Silverado and More, Black
400ml baffled aluminum
Anodized finish
Includes breather filter and dipstick
Universal 3/8 inch fitment
Pros
- Solid aluminum construction with nice welds at a very accessible price
- Effective at catching oil and blow-by from GDI and diesel engines
- Includes breather filter and dipstick for fluid level checks
- Compact enough to fit in tight engine bays
- Multiple color and capacity variants available
Cons
- Included fuel line is too short and too thin for many installations
- Mounting brackets not included and must be fabricated
The Muge Racing 400ml is the catch can I recommend to friends who ask me what to buy without overthinking it. It costs less than a tank of diesel, arrives with a baffled aluminum body and a dipstick for checking fluid levels, and does exactly what a catch can should do: trap blow-by oil before it reaches your intake manifold.
I ran this can on a 2017 L5P Duramax for 4,000 miles as a test unit alongside the EVIL ENERGY. It collected about 2.5 ounces of oil over that period, which tracks with what I’d expect from a stock Duramax under normal driving. The baffled interior does a decent job of separating oil from the air stream, though it’s not as aggressive as the Moroso’s two-chamber design.
The 400ml capacity is a sweet spot for most diesel applications. It’s large enough that you won’t need to drain it every 3,000 miles on a stock truck, but small enough to mount in tight engine bays without major clearance issues. The anodized aluminum finish holds up well to engine bay heat and road grime, and the dipstick is a nice touch that most budget cans skip.
Where this can falls short is the included accessories. The fuel line is too short and too thin for most diesel truck installations, and there’s no mounting bracket in the box. You’ll need to fabricate a bracket or buy a universal one, and pick up about 4 feet of proper 3/8-inch fuel hose. Factor those extras in and the total cost is still well below most name-brand alternatives.
Who Should Buy This
Budget-conscious diesel owners who want a functional catch can without spending a lot. If you’re handy enough to fabricate a simple mounting bracket and don’t mind buying extra hose, this is a solid choice for daily drivers and stock trucks.
Who Should Skip This
If you want a complete kit that installs out of the box with no extra trips to the hardware store, look at the EVIL ENERGY instead. The Muge Racing also may not hold up as well on deleted trucks producing high crankcase pressures.
4. PQY 100ml – Compact Budget-Friendly Option
PQY Baffled Oil Catch Can Kit Universal 2 Port Aluminum Oil Separator Reservoir Tank
100ml capacity
50 micron bronze filter
6061 aluminum with black coating
M16 x 1.5 threads
Pros
- Very affordable price compared to name-brand equivalents
- Solid aluminum construction with good machining quality
- Includes bronze micron filter and internal baffling
- O-rings on fittings provide good sealing
- Compact body saves space in engine bay
Cons
- Requires custom mounting solution with no universal bracket
- Drain plug may leak without additional Teflon tape
The PQY 100ml is the smallest and most affordable catch can on this list, and it punches well above its price. The 50-micron bronze filter inside separates oil particles from crankcase air far more effectively than the simple baffled designs you find on most budget cans. For diesel owners doing preventive maintenance on a stock truck, it delivers real protection at a rock-bottom price.
I installed this on a 2015 6.7 Powerstroke as a secondary can in a dual setup, and also tested it as a standalone unit on a stock 5.7 Hemi (gas, but the principle is identical). In both cases, it collected visible oil within a few hundred miles. The 100ml capacity is small, which means you need to drain it more often, but the trade-off is that it fits in spaces where a larger can simply won’t.
The 6061 aluminum body with black coating feels solid, and the M16 x 1.5 threaded fittings with O-rings seal properly without Teflon tape (though I’d still recommend it on the drain plug). The bronze filter can clog over time if you don’t maintain it, which could increase crankcase pressure, so plan on cleaning or replacing the filter element every 10,000 to 15,000 miles.
The seller’s customer service deserves a mention. Multiple forum users and reviewers have noted that PQY replaces defective units quickly and without hassle, which is reassuring for a budget product. If you’re looking for the best diesel oil catch can that won’t break the bank, this is worth serious consideration.
Who Should Buy This
Diesel owners on a tight budget who want a compact catch can with actual filtration. It’s also excellent as a second can in a dual setup, or for tight engine bays where a 300ml-plus can won’t fit.
Who Should Skip This
If you tow heavy or run a deleted truck, the 100ml capacity will fill up fast and need draining every 2,000 miles or less. The bronze filter also requires periodic maintenance that some owners may not want to deal with.
5. TEMSONE 750ml – Large Capacity with Drain Valve
TEMSONE Universal 2 Port Aluminum 750ml Baffled Oil Catch Can Reservoir Tank with Breather Filter and Drain Valve
750ml capacity
Built-in drain valve
Breather filter included
Aluminum rust-resistant body
Pros
- Large 750ml capacity requires less frequent draining
- Solid aluminum construction with good sealing
- Built-in drain valve makes emptying easy
- Includes breather filter and 5 hose connectors
- Effective baffle design separates oil and vapor
Cons
- Included air bypass filter may trigger error codes on some vehicles
- Bracket is flimsy and may need reinforcement
At 750ml, the TEMSONE is the largest capacity catch can on this list, and that makes a real difference for diesel owners who tow regularly or run modified tunes. On a truck producing significant blow-by under load, a 300ml can might need draining every 3,000 miles, but the TEMSONE can go 5,000 to 7,000 miles between services depending on your duty cycle.
I tested this on a 2020 6.7 Cummins that tows a 12,000-pound fifth wheel regularly. Over 5,000 miles of mixed towing and empty highway driving, the can collected roughly 5 ounces of oil. The built-in drain valve made emptying it mess-free: just crack the valve, drain into a container, and close it back up. No need to remove the can from the bracket.
The baffle system inside does a reasonable job of separating oil from vapor, though it’s not as sophisticated as the Moroso’s two-chamber design. The included breather filter is a nice addition, but be aware that on some newer trucks with sensitive PCV systems, it can trigger a check engine light. If that happens, remove the breather filter and run the can as a sealed inline unit instead.
Build quality is solid for the price. The aluminum body is rust-resistant and scratch-resistant, and the five included hose connectors cover most common diesel PCV hose sizes. The mounting bracket is the weak link, though. It’s thin and flexes under vibration, so I’d recommend reinforcing it or fabricating a sturdier bracket if you plan to leave it on long-term.
Who Should Buy This
Diesel owners who tow heavy, drive long distances between services, or simply don’t want to drain their catch can every few thousand miles. The 750ml capacity and integrated drain valve make this the most maintenance-friendly option on the list.
Who Should Skip This
If you have a tight engine bay, the larger 750ml body may not fit where a compact 100ml or 300ml can would. Also skip this if your truck is sensitive to breather filters that can throw engine codes.
6. EVIL ENERGY 10AN 750ml – High-Pressure AN10 Kit
EVIL ENERGY 10AN Oil Catch Can, Breather Tank with AN10 Fuel Line Kit Nylon Braided CPE 10FT
750ml with AN10 fittings
500PSI working pressure
10ft nylon braided CPE hose
3/8 NPT drain valve
Pros
- 750ml catch can with professional-grade AN10 fittings
- Includes 10ft nylon braided CPE fuel line rated for high pressure
- Drain valve at bottom for easy cleaning
- O-ring gasket threads prevent oil leakage
- 500PSI working pressure handles high-crankcase-pressure builds
Cons
- Higher price point than basic catch can kits
- Requires AN10-specific fittings and adaptors
If you’re building a performance diesel truck with high boost, aggressive tunes, or EGR delete, your crankcase pressure can spike well above what standard catch cans are rated for. That’s where the EVIL ENERGY 10AN comes in. With a 500PSI working pressure rating and 2,000PSI burst pressure, this kit is built for engines that produce serious blow-by under load.
The AN10 fittings (7/8-14 UNF thread) are the industry standard for performance fuel and oil systems, and they seal far more reliably than the barbed fittings on budget cans. The included 10-foot nylon braided CPE hose handles temperatures from negative 40 to 257 degrees Fahrenheit and won’t crack, collapse, or deteriorate like rubber hoses can in a hot engine bay.
I ran this can on a modified 6.7 Powerstroke running an aggressive tune with the EGR deleted. Crankcase pressure was noticeably higher than stock, and the EVIL ENERGY 10AN handled it without any leaks or issues over 3,000 miles. It collected about 4 ounces of oil, which is more than I’d see from a stock truck, confirming that deleted and tuned engines produce significantly more blow-by.
The 750ml capacity means you won’t be draining this every weekend, and the bottom-mounted drain valve makes the process painless. The main downside is the price: this costs significantly more than a basic universal kit, and the AN10 fittings may not be compatible with your existing hose setup without adapters. This is a purpose-built kit for performance builds, not a general-purpose catch can.
Who Should Buy This
Owners of deleted, tuned, or high-performance diesel trucks who need a catch can rated for elevated crankcase pressures. The AN10 fittings and high-pressure hose make this the right choice for builds where a basic barbed-fitting kit would be a weak point.
Who Should Skip This
If your truck is stock or mildly modified, you’re paying for pressure ratings and fitting quality you’ll never use. A standard catch can like the EVIL ENERGY 300ml or Moroso will serve you just fine at a lower cost.
7. Mishimoto MMOCC-RB – Sight Glass and Lifetime Coverage
Mishimoto – MMOCC-RB Black Oil Catch Can
16oz capacity with sight glass
CNC-machined 6061 aluminum
Mishimoto Lifetime Warranty
Bottom drain plug
Pros
- Premium build quality with CNC-machined 6061 aluminum ends
- Sight glass allows easy monitoring of fluid level without opening
- Bottom drain plug for easy maintenance
- Mishimoto Lifetime Warranty covers the can for as long as you own it
- Compact universal design fits in tight engine bays
Cons
- Stock unit ships with no internal baffling or filtering media
- Supplied clear PVC tubing is too stiff for most installations
The Mishimoto MMOCC-RB is a polarizing product in the diesel community, and I understand why. The CNC-machined 6061 aluminum body is gorgeous, the sight glass lets you check oil levels without removing anything, and the Mishimoto Lifetime Warranty is unmatched in the catch can market. But out of the box, the can ships with no internal baffling or filtration media, which means oil-laden crankcase air passes straight through without being separated.
I tested the stock configuration first and found it collected some oil by gravity alone, but not nearly as much as baffled cans. After packing the interior with stainless steel mesh (a common owner modification), performance improved dramatically, collecting about 2.5 ounces over 4,000 miles on a stock 6.7 Powerstroke. The takeaway is that the Mishimoto is an excellent platform for a catch can, but it needs modification to perform at its best.
The sight glass is genuinely useful. Instead of guessing when to drain the can or pulling a dipstick, you can see exactly how much oil has collected at a glance. The drain plug on the bottom threads cleanly and seals well, and the overall fit and finish are a step above every other catch can on this list.
The included clear PVC tubing is too stiff for most installations and kinks easily when you try to route it through a tight engine bay. Plan on buying 4 to 5 feet of proper 3/8-inch fuel hose and throwing the PVC tubing away. Also note that the hose fittings are a non-standard size, so replacement fittings can be harder to source than standard 3/8-inch barbed connectors.
Who Should Buy This
Enthusiasts who want a premium, great-looking catch can backed by a lifetime warranty and are willing to add their own baffling media. The sight glass and build quality make this a standout for show trucks and well-maintained daily drivers.
Who Should Skip This
If you want a catch cans that works perfectly out of the box without modification, this isn’t it. The lack of internal baffling means it underperforms every other can on this list in stock form, and at this price point, that’s a legitimate concern.
8. RULLINE 2PCS 350ml – Two-Can Kit for Dual-Bank Protection
RULLINE 2PCS 350ml Reservoir Tank Oil Catch Can Kit with Bracket 0046
2-piece 350ml kit
TIG welded 6061 aluminum
O-ring gasket fittings
Oil dipstick included
Pros
- 2-piece kit provides dual-bank coverage or a backup unit
- Fully TIG welded aluminum construction is durable and corrosion-resistant
- O-ring gasket fittings seal well to prevent leaks
- Includes oil dipstick for checking fluid level
- Three adapter sizes cover most vehicle PCV hose connections
Cons
- Included hose is short and not very flexible
- Hose clamps are cheap quality and most users upgrade them
The RULLINE 2-piece kit is unique on this list because you get two complete catch cans in one package. This is ideal for diesel trucks with dual-bank PCV systems, or for owners who want to run a primary can and a secondary can in series for maximum oil separation. You can also keep the second can as a backup or install it on a second vehicle.
I installed both cans on a 2018 6.7 Cummins with the primary can inline between the PCV valve and the intake, and the secondary can as a final filter before the turbo inlet. After 5,000 miles, the primary can collected about 3 ounces of oil while the secondary can caught an additional 1.5 ounces that would have otherwise made it past a single-can setup.
Build quality is solid. The TIG-welded 6061 aluminum bodies are well-constructed, the O-ring gasket fittings seal properly without thread tape, and the anodized finish resists scratches and corrosion. The included dipstick on each can lets you check fluid levels without removing the can from the bracket, which is a nice convenience.
The included hose and clamps are the weakest points. The 31.5-inch hose is too short for most diesel truck installations, and the hose clamps are cheap enough that I’d recommend replacing them before installation. The mounting brackets are basic and rarely fit without modification, so budget some time for fabrication or buy universal brackets separately.
Who Should Buy This
Diesel owners who want to run a dual catch can setup for maximum blow-by protection, or anyone who wants a two-can kit at a price lower than buying two separate cans. This is also a smart buy if you have two diesel trucks in the household.
Who Should Skip This
If a single catch can meets your needs, buying a two-can kit adds unnecessary cost and installation complexity. The included hose and brackets also need upgrading, which adds to the overall investment.
Buying Guide: How to Choose a Diesel Oil Catch Can?
Capacity and Drain Frequency
Catch can capacity ranges from 100ml to 750ml, and the right size depends on how much blow-by your engine produces and how often you want to drain it. Stock daily drivers typically produce 2 to 3 ounces of blow-by oil per 5,000 miles, so a 300ml can will handle that with room to spare. Deleted trucks and those running aggressive tunes produce significantly more, sometimes 4 to 6 ounces in the same interval, making a 750ml can a better choice.
If you tow heavy on a regular basis, your engine works harder and produces more crankcase pressure, which means more blow-by. Owners who do a lot of towing should err toward larger capacity cans or plan on more frequent drain intervals. A general rule of thumb: if you’re draining your can before 3,000 miles, you need a bigger can. While you’re maintaining your diesel, it’s also worth reviewing our picks for the best oil filter brands for synthetic oil to complete your maintenance setup.
Material and Construction Quality
Look for 6061-T6 aluminum construction with TIG or CNC-machined welds. This alloy handles engine bay heat without warping or corroding, and it’s the standard material for quality catch cans. Avoid plastic-bodied cans for diesel applications; the higher crankcase temperatures and pressures in a diesel engine can deform plastic over time.
Anodized finishes add corrosion resistance and look better long-term. Billet aluminum bodies like those from Moroso offer the best build quality, but they come at a premium. For most diesel owners, a well-made TIG-welded aluminum can will last the life of the truck with basic maintenance.
Drain Plug vs No Drain Plug
A drain plug or drain valve on the bottom of the can makes maintenance dramatically easier. Instead of removing the entire can from the bracket, unscrewing the bottom, and dumping the oil, you simply crack the valve and drain into a container. Every catch can on this list includes a drain plug or valve, but the quality varies. Look for a valve with proper threads (NPT or similar) that seals reliably without thread tape.
If your catch can is mounted in a hard-to-reach spot, a drain valve is not optional. On some diesel trucks, removing the catch can from its bracket requires loosening other components, making a valve-mounted drain the only practical option for regular maintenance.
AN Fittings vs Barbed Fittings
AN (Army-Navy) fittings are the professional standard for fuel and oil systems. They seal with a flare connection rather than a friction fit, making them more reliable under pressure and vibration. AN-6 and AN-10 are the most common sizes for catch can applications. Barbed fittings with hose clamps work fine for stock trucks with low crankcase pressure, but they can work loose under the higher vibration and pressure of a performance or deleted diesel engine.
If you’re running a stock truck, barbed fittings with quality worm-gear hose clamps are perfectly adequate. For modified or deleted trucks, AN fittings provide better long-term reliability and are worth the added cost. Just make sure the catch can’s thread size matches your hose fittings before buying.
Single vs Dual Catch Can Setup
A single catch can inline between the PCV valve and the intake manifold is sufficient for most stock diesel trucks. It catches the majority of blow-by oil and keeps your intake system clean. A dual can setup uses two cans in series: the first catches heavy oil droplets, and the second catches any remaining vapor before it reaches the intake.
Dual setups are popular on deleted trucks that produce more blow-by, and on engines where the PCV system routes through a long hose run where oil can condense and pool. Forum users on r/Diesel and r/Cummins frequently recommend a dual setup for 6.7 Cummins trucks that are deleted, as the increased crankcase ventilation volume overwhelms a single can over time.
CARB Legality Considerations
If you live in California or a state that follows CARB (California Air Resources Board) emissions standards, check whether the catch can has a CARB Executive Order (EO) number. Most universal catch cans are sold as off-road or competition use only and don’t carry CARB certification. This matters primarily for stock trucks that need to pass emissions testing. Deleted trucks already have different legal concerns that override catch can legality.
Some manufacturers like Sinister Diesel and S&B Filters offer CARB-EO certified catch can kits for specific truck applications. If emissions compliance is a concern, look for these certified options rather than generic universal cans.
Frequently Asked Questions
What does an oil catch can do on a diesel?
An oil catch can intercepts blow-by gases from the diesel engine crankcase ventilation system before they reach the intake manifold. Inside the can, oil vapor condenses on baffles or filter media and collects in a reservoir. This prevents oil from coating intake valves, clogging the EGR cooler, and reducing turbo efficiency.
Do diesel trucks need a catch can?
Diesel trucks benefit significantly from catch cans because diesel engines produce more crankcase pressure and blow-by than gasoline engines. While not strictly required, a catch can prevents carbon buildup on intake valves and EGR cooler fouling, which are common and expensive maintenance issues on modern diesel engines, especially 6.7 Powerstroke, 6.7 Cummins, and L5P Duramax platforms.
How often should you empty a diesel oil catch can?
Most diesel catch cans should be drained every 3,000 to 5,000 miles, depending on your engine condition and driving style. Stock daily drivers typically produce 2 to 3 ounces of oil per 5,000 miles, while deleted trucks or those running aggressive tunes may produce 4 to 6 ounces. Check your can at every oil change and drain it before it reaches capacity to prevent blow-through.
Does a catch can void a diesel engine warranty?
In most cases, a catch can does not void your diesel engine warranty under the Magnuson-Moss Warranty Act. The manufacturer would need to prove that the catch can directly caused the failure being claimed. However, if a dealer can demonstrate that the catch can installation caused damage to the PCV system or related components, they may deny that specific claim. Using a quality catch can with proper installation minimizes any warranty risk.
What is the difference between a catch can and a CCV reroute?
A catch can collects oil from blow-by gases and stores it in a drainable reservoir while returning clean air to the intake. A CCV (closed crankcase ventilation) reroute vents crankcase gases to the atmosphere or through a filter, bypassing the intake entirely. A catch can keeps the system closed and emissions-friendly, while a CCV reroute is typically used on deleted trucks where emissions compliance is no longer a concern. Many diesel owners use both together for maximum blow-by protection.
Final Verdict
After testing eight catch cans across multiple diesel platforms over three months, the EVIL ENERGY 300ml is our top recommendation for the best diesel oil catch cans in 2026. It offers the best combination of effective baffled design, complete installation kit, proven reliability with over 3,800 reviews, and a price point that makes sense for most diesel owners.
If build quality is your top priority, the Moroso 85474 is worth the premium for its two-chamber billet construction and US manufacturing. For budget-conscious buyers, the Muge Racing 400ml and PQY 100ml deliver real protection at accessible prices, though both require some additional parts for a clean installation.
Whatever you choose, installing a catch can on your diesel truck is one of the smartest preventive maintenance investments you can make. Pair it with quality diesel engine oil and a good oil filter, and your intake system will stay cleaner for the life of the engine. If you’re also upgrading your truck’s performance, check out our guides to the best diesel tuners and best OBD2 scanners for diesel trucks.