so im wondering, i know injen has a working ses headerback exhaust that doesnt cause any cel issues. if i go down to my local autobody that as a mandrel bending system and get a custom flowmaster exhaust installed for my pzev, is there anything special that has to be done in order for it to not throw any cels? be that a high flow cat or positioning of the o2 sensor bung?

 

the special stuff will be the high flow cat, and the O2 sensor position, like you already mentioned.

While you're under there customizing stuff, you could replace the stock pre-cat with a Flowmaster 'high flow' Pre-cat too.

 

i thought the pre-cat was inside the stock exhaust manifold. does flowmaster have a replacement for that now too? will they know exactly where to place the o2 sensor on this new exhaust and will any high flow cat work? i wanna get all these answers first before i look like a newb down at the autoshop.

 

I haven't gone that far under my car yet, but I doubt the pre-cat is "inside" the exhaust manifold. Worst case scenario, it's welded to the stock manifold.

Flowmaster makes the Pre-Cats.

If you're having a muffler shop do this stuff to your car, they should be knowledgeable enough to know where to place the sensors to prevent CELs.

 

Why do you doubt it? The precat was inside the exhaust manifold on my 2002 Lancer...