Well, you can always mess with the Exhaust, and one of my buddies is going to adjust the timing on mine and I'm gonna put a home made cold air intake on the 2.3

 

yeah, pacesetter makes a pretty good exhaust manifold. Full length and the only down side is that you need to know how to solder, your going to have to extend the wires of the O2 sensor to make it work. I have that on mine right now going into a 2 1/4" exhaust system, no CAT, and i have it running through a flowmaster 40 series muffler. I will admit, it is a little on the louder side, but it sounds awesome! I also made a pvc cold air intake for mine and it seems to work pretty good too. Just watch out of puddles on the right side of your car if you drive it in the rain!