im going to be putting a new exhaust on my mustang soon and l want it to stay legal. the only problem is those damn catylic converters! they rob HP and sound. anyone have any good converters that dont hurt HP or sound for muscle cars?

Highflow cat is your best legal option.

try easterncatalyticconverter.com or shopmufflers.com

go magnaflow

Any catalytic converter will cut into power output to a degree. The good news is that a good high flow catted H/X pipe will easily outperform the stock H-Pipe, while still remaining emissions legal.

l had a MAC 2.5'' Catalytic H-pipe on my '98 GT & it definitely resulted in a seat of the pants improvement, especially after l head swapped the car.

An offroad pipe will also be louder, but with the catted H-Pipe & 40 Series Flowmasters my Mustang was pretty damn loud. The resonance inside the car was livable though, & made highway driving completely tolerable.