as of right now i have an ebay testpipe/resonator and I wanna put a high flow cat(real) back on such as a magnaflow or something of that nature. my ques. is what size cat should i get??? I have a dc header and a greddy evo exhaust and the car is just way too loud for my liking, and it sounds kinda shitty. loud was cool when i got the exhaust, but im a little older now and just want something mellow.
my greddy was nice and quiet once upon a time, help me bring it back to its former glory....

 

just measure the size resonator thats on there not and then go from there. or you could just but any can of the same diamiter piping and weld it on. fyi the greddy evo is a little smaller that 2.5"

 

as of right now i have the resonator in place of the cat, with a greddy evo cat back.
Now....my plan is to leave the resonator in place of the cat and weld the high flow cat infront of the resonator on the exhaust so that i will have 2 resonators and one catalytic conv. on my car. hopefully this will tame the exhaust note a lot.

 

a real cat makes a huge diffrence in the exhaust sound. i went from an evo2 with a resonator in the place of the cat. to a 3" turbo back with a cat, 1resonator, and dynomax muffler. i can hardly hear my car at idle. the intake and turbo are much louder than the exhaust. im probly going to take the cat out after i try to pass emissions to help the turbo spool a little quicker.

 

if u take off your test pipe lemme get it