Need exhaust advice please.

[Griever423]

So I purchased some headers for my 2001 Sentra SE. They're going to be bolted up to the stock exhaust soon.

After that, I'm going to have a shop weld me up a custom cat back. The question is, is the stock cat really restrictive enough to noticeably hinder performance. I mean, it wont be but a 2-5 HP gain by cutting it out, and a high flow cat will yield even poorer results. I also want to weld in a resonator to help keep the sound down. Am I really going to be sacrificing a noticeable difference in HP by keeping the stock cat, and welding in a resonator (and yes, I know I have a stock resonator, I'm taking that one out)?

Someone help me out please, haven't really done much exhaust work before.

[nametakennow]

The stock cat is 2.5in in/out and is actually sourced from Calsonic (along with the rest of the stock exhaust). With just exhaust and a header it's not really worth replacing.

It's a good idea to ditch the stock resonator. Use a straight-through perforated and wrapped core design (like a Magnaflow) and you really don't lose any power.

[raymundojr]

you have just to see if the magnaflow would fit depend in what is the make of your car.

[nametakennow]

Resonators are universal. As long as it's not too long, it will fit. I have a 13in, and I'd be willing to bet that at least a 22in res would fit between the cat and the axle bend without even a hint of a tricky welding issue to be had.