Rip it out!
 

Hello,

I live in an area of Arizona that does not require emissions tests. What can I take out of a 2002 Mustang Base Model that will increase over all hp. Also will running straight pipe give a noticeable power boost?

I'd say you will loose power going straight, then get a check engine light, and use more gas, and be slower.

You could do a full exhaust setup and just take off your cats, thats about it.