header questions

[02maxSE]

i was wondering if there's anyone on here that knows how much power do the headers on a 02 max hold back? if i get a catback, high flow cat and y-pipe will that be enough increase i can feel? our headers ain't cheap either!! which catback has a nice deep sound all around the pwr band? don't wanna sound like a bumble bee!!
Modified by 02maxSE at 12:05 PM 4/4/2008

[whynomaximainforza2]

The exhaust manifolds (headers) on the 02 Maxima do hold back quite a bit of power from what I understand because of the two pre-cats. I have a custom y-pipe, hi-flow cat, and Cattman cat-back exhaust and I could definitely feel a difference, but it was not overwhelming, which is to say that I was hoping to feel more of a difference. My next mod is going to be the Cattman headers. I have seen posts claiming a 20-30 whp gain from Cattman and others.

I am very happy with the exhaust note from the Cattman cat-back exhaust.

[Q45tech]

Pretty easy to measure exhaust back pressure say at 1st O2 sensor bung and translate PSI into a percent of possible impovement.

Rarely can any amount of exhaust redesign yield more than 10%, less [say 4-5%] if you must mainatain legal emissions and can only work after the last cat in sequence.

If you emission tamper [say high flow cats or worse] you may get stuck in future restoring to oem to correct for a future owners failure to pass so always keep old parts.