First, PCV factory setup. Is there a better way? Is a catch can a good idea, overkill, or somewhere in between? Just wanting to hear thoughts and suggestions on this.

Second, the factory air injection system. Really necessary? Any of you deleted it with positive results or even no difference either way?

 

The PCV system can absolutely not be removed, your blow-by will quickly start blowing out gaskets and pushing oil out. You can add a catch can while retaining the PCV. Several companies offer these.
https://www.eliteengineeringusa.com/...tte-1997-2004/


Removing the AIR system will buy you nothing performance wise.

 

Thanks for the reply. I know the PCV system is a necessary component but it does seem to be somewhat convoluted. I have my intake off at present and inside the manifold and on much of the intake runners there is a coating of a black sticky oily substance. The stickiness was the surprise for me. Also it was obvious that the spray pattern of the injectors was keeping parts of the intake runners (in the heads) completely clean. I also noted that there was no noticeable carbon buildup on the valves that I could detect. All in all maybe not too bad for 88,000 miles and 26 years of service?


Performance improvements are always welcomed but not the only reason I do things. The AIR system appears to be another convoluted mess which I am questioning it’s significance. I’ll admit my ignorance on why it was “necessary” in the first place. I do have a 95 Impalas SS that I added headers and eliminated the cats (no O2’s on the LlT1’s) and got rid of the air pump and associated parts and pieces with no I’ll effects and cleaned up the engine bay nicely.

 

Look into the 2004 LS6 PCV system upgrade/conversion. It uses a different valley plate and hoses and eliminates the external PCV valve.

The AIR system is purely emissions related. Obviously it has lots of pieces which can wear out / fail, and is only used for a brief period of time at cold start (to help the cats warm up faster). You certainly could remove it and have your tune revised accordingly, but as noted it won't net you performance although you could shed a few pounds and have less equipment to fail in the future.

 

Now this is what I’m talking about, thanks! I have a ls6 valley plate too, probably why I picked it up. I look into it further.

 

Just make sure it's a 2004 LS6 or 2005+ LS2. 2001-2003 LS6 PCV is different.

 

This recent thread should answer all of your questions about the PCV system and catch cans. Kingtal0n has given a lot of good information in this thread.

https://www.corvetteforum.com/forums...cuum-pump.html

 

Now you tell me! I have no memory of what year I bought, but thanks for the heads up! I appreciate it.

 

Thankyou for the link!

 

Just to close the loop on this, the late LS6 valley plate part number is GM 12577927. You also need the molded PCV fresh air hose GM 12594779.

 

I still have the AIR parts on the car but had the system tuned out after it caused the car to fail emissions testing, in 2024. Passed with no issues, in 2025.
Now that the car is 25yrs old, it's exempt from further emissions testing.