highflow cat

It shouldn't be I/H/E, it should be I/H/C/E

Right now your cat is a boltneck for you header and exhaust. You have a 2.25" exhaust (or larger) yet a 2" cat, that not only has poor flow ability but is more than likely plugged from seven years of driving.

www.ipsracing.com sells bolt on carsound cats for $200 or so.