The "Catch Can" Explained!

[90503]

My Rx Catch-Can story......

.....Dear Diary,

Had a cel lately go on and off...thought I'd take a look under the engine cover...

I have the breather, and therefore the vent hose from the intake was removed and the two rubber supplied caps were installed...one on the cai, and the other on the "manifold vent"(?)...hope that's what it's called...

Anyway, the cap on the manifold tubing was completely....gone!!...And the one on the cai was all cracked and barely hanging on...

I replaced the vent hose, removed the breather and went back to the regular oil filler cap...Car never ran bad, just a cel once in a while...no idea how long the cap was missing...

....Just thought I'd pass that along...My caps didn't hold up very well...

...Also, while I was at it, I teed the inlet hose to the catch-can over to the driver's side valve cover (and the passenger valley cover, where it was originally)....

Cel is off...don't think I really hurt anything...and was wondering if how I teed over to valve cover and valley cover is an ok thing to do...thanks...Tom

P.S. I have a garden variety LS3...no major mods....

[Sevn86]

Nice!

[stardok]

Sounds like a catch can is good for the motor. Would it void the new car warranty? Thanks.

[90503]

Originally Posted by stardok

Sounds like a catch can is good for the motor. Would it void the new car warranty? Thanks.

Not sure, but I think on your ZL-1 it already has something like the can good to go...I could be wrong, but I don't think ZL1s need them...

[Apex Motorsports]

Originally Posted by stardok

Sounds like a catch can is good for the motor. Would it void the new car warranty? Thanks.

It is a great investment in the long term health of your engine. It will not void your warranty.

Originally Posted by 90503

Not sure, but I think on your ZL-1 it already has something like the can good to go...I could be wrong, but I don't think ZL1s need them...

The ZL1 does not come with a catch can.

[SC2150]

No warranty issues, GM dealers buy a ton of these.

Any questions I missed let me know.

[Apex Motorsports]

Originally Posted by SC2150

No warranty issues, GM dealers buy a ton of these.

Any questions I missed let me know.

Welcome back!

[ssmike]

Tracy, I have an RX catch can and recently had the car dyno tuned. The tune turned out great but I noticed on the way home (3 hour drive) when pulling in to a rest area and slowly cruising and idling I heard a vibration and rattle. I thought it was the exhaust so when I got home I jacked it up but all was tight. The source of the rattle was the catch can. When I heard the noise the catch can was kind of making a fizzing sound and you can hear the check valve vibrating inside. This would happen for a minute or 2 then stop, then start again and repeat the cycle. I have had it installed for about a year and 1/2. I recently moved it from the normal position over to the passenger side where the OE air intake used to be (I'm using a Vararam) and now there's 3' of hose on the in and 3' of hose on the out, routed under the TB.

I removed the catch can hoses and re-installed the OE hose between the valley cover and IM. No more noise but now the problem is I've lost some throttle response and it's kind of sluggish. Can the catch can, or removal of it, cause problems with the tune. If it was tuned with it installed and now I removed it what affect will it have on the tune? Also, why is it making this racket? I had one when I first bought it from you that made the same noise and you replaced it.

Thanks!

[SC2150]

If the engine is NA you can simply replace the valve with a 1/4 NPTx3/8" barb 90* fitting.

Usually when you here excess sound the drain valve is open by mistake.

[Apex Motorsports]

Bump for educational purposes.

[RJT-SS]

Did you put a topic together on choosing the "right" exhaust and how stock exhausts work? It's kinda a trick question as this is probably the single hardest mod to get "educated" on due to the subjectivity of volume and tone. Great work on putting these topic threads together!!

[Chad 2012 RS]

Will installing a catch can affect the warranty at all? Also, why doesn't GM offer them as an option?

[Chad 2012 RS]

Woops, never mind the warranty question....

[Apex Motorsports]

Originally Posted by RJT-SS

Did you put a topic together on choosing the "right" exhaust and how stock exhausts work? It's kinda a trick question as this is probably the single hardest mod to get "educated" on due to the subjectivity of volume and tone. Great work on putting these topic threads together!!

You are probably thinking about:

Choosing The Right Long Tube Headers

Thanks!

Originally Posted by Chad 2012 RS

Will installing a catch can affect the warranty at all? Also, why doesn't GM offer them as an option?

Here is a link to another thread I wrote that discusses the relationship between modifying your car and warranty law.

Will This Modification Void My Warranty?

There is a clean side system included with the 1LE Camaro and they are included on some performance cars that are a little higher up the economic scale. I do not have access to the places where those decisions are made at GM but I would suspect that for most of the automotive manufacturers it is just a simple business decision. Do you incur increased costs ($100 isn't much until you multiply it times 100,000+ units a year and realize that is right out of your profit) to add a catch can to fix something that will not be a serious issue until after your warranty has expired? Do you add a system that requires the owner to do a maintenance process they are not familiar with and possibly ignore (draining the can) that then could potentially cause an issue within the term of your warranty? It is probably as simple as that.