Catch Can Kits

Capacity controls how often you drain, not how well the can filters. A 300 ML can and a 3L can separate oil the same way. Owner data across LS, EcoBoost, Hemi, and diesel platforms lands near 1 fluid ounce of collected fluid per 1,000 miles on a healthy street engine, and closer to 2 ounces per 1,000 miles on a boosted, towing, or track driven build. Because you should drain at half full and never past two thirds, the math works out like this:

• 300 ML Oil Catch Can covers a stock or lightly tuned naturally aspirated daily driver for a full 3,000 to 5,000 mile oil change interval.
• 750 ML Oil Catch Can is the safe pick for turbo and supercharged street cars, LS swaps, and trucks that tow, giving real headroom between services.
• 1L, 2L, and 3L Oil Catch Can exist for track weekends, off road running, high blow by diesels, and vented breather setups where you do not want to service between events.

The most reliable method is to install the can, drive 500 miles, then drain and measure. That single number tells you your own interval better than any chart.

Almost every street driven vehicle needs the sealed configuration. You install the can inline between the existing PCV hoses with no breather filter fitted, so cleaned air still returns to the intake. Manifold vacuum keeps evacuating the crankcase, fueling stays correct on MAF equipped cars, there is no burnt oil smell, and the emissions circuit stays closed for state inspection and smog.

Fit the breather filter instead only when blow by volume outruns what a vacuum driven PCV loop can evacuate, which typically means high boost, race, or pre PCV vintage builds. Venting crankcase gas to atmosphere is not emissions legal for street use in most US states, and on a modern MAF equipped car it also creates an unmetered air path that upsets fuel trims.

Two points worth stating plainly: these cans do not contain a PCV valve, your factory PCV valve stays in the system and the can sits downstream of it. And every EVIL ENERGY kit on this page ships with the breather filter included, so choosing one setup now does not lock you out of the other later.

Check the can at every oil change as a baseline, and drain it when it reaches roughly half full. On a boosted or hard driven car, move that to every 1,000 to 2,000 miles. A can that overfills will start pushing collected oil back toward the intake, which defeats the entire purpose of the install.

Winter is a different regime and this is where most people get caught out:

• Cold air condenses far more water out of the blow by stream, so volume can run two to three times the summer rate and the fluid drains milky rather than dark.
• The real hazard is not the can freezing, it is a frozen hose. If a line ices shut, crankcase pressure has nowhere to go and can push oil past the rear main seal or valve cover gasket.
• Route your lines with a continuous downward slope into the can and no sagging low spots where water can pool, and mount the can somewhere that gets engine bay heat.
• Below freezing, check the can weekly rather than by mileage. A useful rule from northern owners: if your windshield had frozen condensation on it, check the can.

Cleaning is soap, warm water, and a rinse. Let the internal media dry fully before reassembly, and never pour the drained fluid back into the sump, it is a mix of oil, water, and unburned fuel.

No, and any brand telling you otherwise is selling you something. A catch can adds no power on day one. What it does is protect the power you already paid for. On a direct injection engine there is no port fuel washing the back of the intake valves, so recirculated oil mist bakes into carbon deposits that restrict airflow, disturb the air fuel mixture, and can eventually cause misfires and knock related timing pull. Oil vapor in the charge also lowers the effective octane of the intake charge, which matters most on a boosted engine running near the knock threshold.

The honest framing: a catch can is preventive maintenance for your intake tract, in the same category as an oil cooler or a fuel filter. It keeps the engine making what it made when it was new, and it is significantly cheaper than a walnut blast service.

These are universal oil catch can kits, which means fitment depends on three things you can verify in five minutes rather than on a year make model lookup:

• Mounting space. You need clear room on a frame rail, inner fender, or firewall panel for the bracket, plus enough clearance to reach the bottom drain valve with a wrench.
• Hose size. Match the AN10 port to your existing PCV hose diameter using the adapters supplied. The 300 ML PCV kit ships with M16x1.5 to AN6, AN8, and AN10 adapters to cover most factory hose sizes.
• Port count. Confirm whether your engine runs one crankcase vent or two.

For an LS catch can kit specifically, the common Gen III and Gen IV setup runs a line from each valve cover vent to the can, driver side from the PCV port and passenger side from the fresh air port. AN10 plumbing is genuinely useful here because it flows more than the 3/8 inch barbs on entry level cans, which matters on a cammed or boosted LS.

For Honda B series and K series, most builds run a single vent line and the 300 ML can is the right size. For diesel trucks including Duramax 2.8 and 3.0, blow by volume is high enough that we would point you to 750 ML minimum, and 1L if you tow.

If you are unsure, send Evil Energy support your engine, boost level, and a photo of your available bay space before you order.