For my cobalt 2.4 I'm looking at either doing a free flowing cat or the cat delete option.. Mostly just to do it, being bored... Which would be the better route to take, or is it even worth it to do at this point in time? Will I have to do anything to the O2 sensor or get a tune..

I still have the stock exhaust, except for an el' cheapo muffler can...

Thanks in advance..

 

A high-flow cat wont net you much of a gain alone. You'd have to be at the bleeding edge of efficiency already, which likely won't happen unless you go with some form of forced induction.

If you really want to go for it though, you will not need to modify anything in the tune since your rear o2 will be in the same place and you will still have a cat. Your volumetric efficiency might change a small amount, but it would hardly merit paying a tuner to modify until you tack on more mods.

If you go catless, you will need to have all your rear o2 DTCs disabled and have your Cat over-temp values deleted.

You could actually go catless without a tune, but you'd have an annoying CEL and you'd be dumping extra fuel to cool down a non-existent cat.

 

Alright, so I'll just hold off on that until I get around to getting a turbo and full exhaust.. Thanks!!

 

I have high flow cat and get a p420 CEL the butt dyno feels better performance with hf cat vs stock cat (had to swap to stock to pass inspection just recently) Even if gains are minimal still better than stock cat lol