Hey guys, My mechanic recently told me that I should remove a custom catch can that has been installed by the previous owner. He reckons it will affect my base idle and is unnecessary with stock management. Also, my car is not very heavily modified (only 3" exhaust, cooler and hi-flow turbo). It has two lines coming out of the rocker cover and into the catch can - one at the nearest part of the cover, and the other at the back. Now I'm guessing that means I'll have to put it back the way it was - meaning the pipe going into the nearest part of the cover goes back into into the plenum. But my prob is this: if I do that, what do I do with the one up the back? Just plug it up? Or run it into the plenum, or even the cooler pipe before it enters the throttle body? If you're reading this and finding it bloody difficult to understand what I'm talking about - let me know, and I'll get some pics up. Any help will be appreciated. Thanks, Bozza.

i understand what ya mean, the one at the back i believe runs to the plenum, but i dont see why you would want to get rid of it, it doesnt matter if you dont have THAT many mods its still better to have one imo.

I doubt it will effect the idle at all. Has it got an idle problem? The plenum will prob have a bung in it where the front pipe used to go, and rear pipe goes back into the intake before the turbo factory. If you have no idle problems, keep it. pics would be helpful though. Cheers.

aerovl is right sorry the back one goes into the intake

well yeah the car does run crap on idle at the moment, but i reckon it's something else, more major, like spark plugs or leads - ie. it needs a good tune maybe. alright well i might just leave this for now, and get some pics up. Thanks

yeah it probably is just that its needs a good tune, cant hurt id ya do that and see how it goes then, im no expert but i wouldnt have thought that the catch can would have a huge effect on ya idle

the PCV system is there for a few good reasons guys, and one of them is to make the engine idle properly. try taking off your oil filler cap while it's idling, then you'll see how a major air leak in the PCV system affects your idle.......

mines fully stock, and has a catch can, no idle problems. It sounds like a case of a bung afm. And your can should be sealed any way unless it has a filter on it) so idle would be the same anyway, goodluck.

yeah, if your catch can is installed properly it won't affect your idle at all

yeah, ie not vented to the atmosphere, there are "proper" ways to install everything

Quote: Originally Posted by StockyMcStock the PCV system is there for a few good reasons guys, and one of them is to make the engine idle properly. try taking off your oil filler cap while it's idling, then you'll see how a major air leak in the PCV system affects your idle....... The PVC system is there purely as an emmision control system, it has nothing to do with your idle. The reason your car runs like crap with your oil cap off is that you have air coming in the oil cap hole, through your PVC pipe and into your air intake ducting after your AFM, so you have unmetered air entering your engine, causing it to run lean and rough.

mate - check your amf setting? should be at 382ohms. a lot of idling problems start with the afm.

hey guys, Just got it back from the mechanic... he checked the AFM, it was fine.. then checked the O2 sensor, and bingo. So he replaced it, and it's all fixed. Catch can is still there, doing it's job (whatever that may be!!) haha nah just jokin - thanks for the info. Much appreciated. Cheers, Bozza