catch can

[kydanny]

99 sl2 125,000 miles. Nothing fancy. All factory.

Lots of confusing details about this catch can a little bit every where. Is it simply a container between the PCV and the throtle body that has no restrictions and gravity pulls the nasties outta the air that passes through? No additional filters (fuel or otherwise) added anywhere..just the pcv as it exists today (maybe switching to an autozone 1009) and a container with an unrestricted in and out spliced into the existing pcv and throtle body connections??

Seems simple but maybe I'm missing something.

[PurdueGuy]

I've seen some that use a no-restriction container, but I've also seen folks use vapor filters for compressed air systems, which is made to pull moisture from the air passing through. It's a low-to-no risk mod that's completely reversible, and many people find they pull quite a bit of oil from it, which otherwise would add to the goop in the intake manifold and/or get burned. I've read, but have not personally had the chance to try to observe, that it can also slightly change your air to fuel ratio and improve power. Theory makes sense, but there are a lot of theories that make sense at first & don't stand up to scrutiny.

[alordofchaos]

I've read about both types as well.

in addition to gravity and filters, you can help the separation of air and oil by having the longer tube (from the PCV side) curved so the air swirls alongside the jar (can't recall which direction, but should be easy to find via search)

I've collected the bits and will get around to this eventually, but plan on using some kind of filter

[td1238]

I made one from a small plastic inline fuel filter. I didn't collect much oil, though, so I removed it and put my engine back to stock. My rebuilt '99 SL2 burns so little oil anyway.

An inline fuel filter sits sideways and cannot be mounted directly above the valve cover, so any oil it collects must be manually emptied back into the engine. A long flat affair might allow for oil return. You could make this out of a naptha can for Zippo lighters or something. Cut it open and solder in baffles, and allow for drainage back to the point of entry.

Alterations in the PCV system will not alter fuel mixture. The fuel mixture in these cars is always being monitored by the O2 sensor, and will be adjusted by the fuel trim. The only way to adjust mixture is to either modify the O2 sensor voltage or to reprogram the computer.

Also, the feed from the PCV system is negligible at any power throttle positions. Alterations are unlikely to affect power.