Okay, I purchase from Intense 42.5# injectors, 2.9 pulley , injector harness , trans axle poly mounts , GM shortened belt and their PCM... Ill be installing this on thursday.. now my main concern is ive heard rumors about the stock Catalytic Converter clocking/breaking and then busting the head gasket etc and frankly im really concerned so im looking for a few answers.. I do NOT want to gut my cat because I HATE CEL's and I would like to pass emissions. If this is the case is there a recommended high flow cat or downpipe/cat comba or what not that I should look into getting I also plan on doing just a lil exhaust work to increase performance but any honest answers would greatly be appreciated. thanks!

 

You could get a dp from CA or ZZP, or the header/dp combo from Vibrant. Either way, the downpipe on the SS is very restrictive and you will get good gains by replacing it.

 

yes I was looking at this

http://www.zzperformance.com/cobalt_...=540&catid=155

but im needing to know if im going to have problems with the stock one because of the major upgrade in performance parts Im doing.... thank you for your reply

 

It depends on how rich the tune runs. I have the GM Stage 2 tune and it of course runs rich. I had to replace my cat at around 20k miles. Of course this was done under warranty. I'm eventually going to go header/dp with the high-flow cat route. I'd suggest the same.