I am currently running kamikazi header & downpipe, rrm test pipe, greddy cat-back. The sound just sucks, if I had to describe the sound id say hold a piece of paper in front of a hair dryer and turn it on and thats the sound. I am going to take out the test pipe and put the stock cat back on, also what is it with our gaskets are they just not normal, I cant find any high temp ones. Id like to go through and replace all the gaskets and put a new metal one in between the downpipe and header, id like that for all of them. Anyone have any suggestions to why its sounding this way, is it the test pipe or an exhaust leak. Thanks
Ryan

 

Oh one other thing would a high flow cat rather than the test pipe make any difference?

 

Highflow should fix the tone a bit (deepen) since it's less freeflowing than a testpipe. Bigger diameter exhaust piping will definitely fix your problem as I've witnessed myself, but that's a much spendier option.

Cheapest to expensivest:
2.5" testpipe
2.25" highflow cat ( which I have for sale... )
2.5" highflow cat

 

2002oz...your experience is proabbly identical to mine..it sounded best when i just had test pipe, and cat back exhaust (magnaflow), and then i got my kamikaze header and downpipe, and it was just way too loud, and raspy..most likely from worn gaskets..so i had all my gaskets replace from local muffler shop, and that helped quita bit, and then it started getting bad again in higher RPMS..like 4k plus it was bad..so i decided to just take off the test pipe and that a huge difference.,,it's now deeper and quieter..so i suggest you just take out the test pipe and you will be happy

 

I have the same problem and plan to take out the test pipe and but the cat in again once it gets warmer in my neck of the woods. haha.