does the cat converter really work?
how much hp gain does it pri\ovide???

how about headers?
is there a aftermarket header available for maxima?

 

Cattman Racing is making headers for the maxima"VQ" motor,They are going to be like 1500+ bucks. they might be out already, im not sure though.
As far as the other question i think you asked if you remove the cat does it add HP,Yes, if you put a high flow it will only add like 1hp(take it off)if you can deal with the noise...Good-luck

 

I was under the impression that the VQ uses exhaust manifolds, not "headers." Putting on headers would be a major deal having to basically removed every extrenal engine component to get in and replace the exhaust manifolds with "headers." Then clearence for these headers is another problem. If he does make them they better had produce ALOT of power for the install you would have to do.

 

Don in Texas took the stock exhaust manifolds and modified them. But, the gains were very minimal. I guess it would only be worthwhile for maximas running forced induction. An aftermarket high flow cat will get you maybe a few hp at most. A y-pipe is by far the most worthwhile exhaust mod.