Hi friends, I just had a question about headers and piping.

I have a p31 already, so I may go with headers /straight pipe resonator/ and x pipe for 2nd cats before a tune... is there any other mod I am going to need in order for this to work without any problems? and.. will smog tests pass? thanks in advance!

 

If you go with headers you'll need a new tune for sure.
Usually people install headers with Xpipe in place of 2nd cat for better HP gains. You can keep the resonator and catback or go with custom mufflers. But it will be extremely loud. Headers are originally loud.
As for the smog test I think it wont pass but I might be wrong.

 

You'll definitely need a tune after installing headers for the engine to run right.

Headers will be loud but there are ways around that to quiet it down. The stock exhausts are like megaphones so you can either get an exhaust with a valvetronic flap or get resonators. The thing with aftermarket exhausts are some people say they drone while others say they don't.

Without cats there's no way your car will pass smog but I don't think you need to smog the car until 5 years down the line in CA.

 

ahhhhh i see. so then tune should be first before I do headers....... hmm

 

No, do it all the same time.

 

You need cats to pass smog. Just have someone fabricate v-band flanges in the midpipes so you can swap them in and out.

 

ok thanks for the heads up guys! appreciate it