Exhaust Mods on 2002GT
 

What do I need to do to my exhaust to increase HP and remain legal (I live in Texas)? I've added a K&N air filter and ordered Steeda pulleys. I figure exhaust should be next followed by 3.73's. Opinions?

I'd run some long tube headers, two-cat h pipe and the muffler of your choice. Most run flowmasters, but dynomax makes good power and sound too.

I don't know about your part of Texas, but here in SETex they don't even look under the car. They pop the hood (sometimes), check the lights, horn, and brakes... that's about it. I know several mustangs that have O/R X-H pipes with no mufflers and still pass inspection every year. I have the BBK H w/ HiFlow Cats (2), and I pass just fine. hell I even had a 1990 model Chevy with a Holley 4bbl mech secondary on top an alum headed engine and they still passed me.. this truck shoud have failed since it is supposed to be TBI not Carb. I think one time they mentioned that I needed to put my preheat tube back onto my air cleaner going down to my headers. -- The only thing they ever tried to fail me for, and this is really stupid, was my Phantom Grille. They tried to say that it caused my headlights to not be seen, (whatever)

i run dynomax, i like the sound. they flow better than flowmaster and dont drone on the highway, they really wont drone with gears because the small bit of drone they have is around 2k-2200 rpm, theyre very quiet from idle to about 1800 rpm if you need to be quiet. i just bought the mufflers, not the complete catback, if you get the complete cat-back go magnaflow.

If I were you (and I wanted the most performance), I would put some 4.10's on your car. They will by far show the most improvement as far as pick up. You could also get any hi-flow system w/ cats. No matter how you look at the math, 2 cats is WAY better than the stock 6 (atleast that's what's on mine). But definitely, gears before exhaust. I went exhaust first--and it's not that I regret it, I just wish I would have done gears first.