Questions about pcm and exhaust

Hi, I recently bought a 2004 pontiac gp gt2 and I was planning on adding a pcm and exhaust to my car. The past few weeks i have been looking at sites such as 3800 and pfyc and I was just wondering what is the best exhaust out there that I can get good quality sound and HP from. Also, with the pcm I have seen a few different ones for this gen's gp so which one would be the best one to go with? Any feedback would be great. thanks

This is a very vague answer because it all depends on what exhaust you like. The sounds can vary by manufacturers so much that it's to hard to narrow it down to one for everybody. A Borla sounds nothing like a SLP!

As for HP gain, a cat-back system is minimal, about 15 HP at the crank. If you do a complete header-back exhaust with a high flow cat or straight pipe you could see some serious gain! Somewhere around 10-15 to the wheels.

PCM's I cannot help with, sorry. I too need to learn about them for future referance!

PCM's are really all about the same... just compare the major features and make sure it has what you want. Also, check and see if the company will do a free reflash for you if somthing happens. All a PCM is is a stock chip thats been tuned so most of the companies do a fine job. buy whats cheaper :-)

ok thanks for the advice i guess ill have to hear the differences between exhausts...............Just one last thing when you say it may need a reflash why is that??? Once I take out the old pcm and put in the new one shouldnt it automatically read? Im still a lil unfamiliar with the pcm

also I had forgot to mention last night i was reading on 3800.com on small things you can do to raise HP and I was just wondering if u new or new any1 that had experience with changing the pulley sizes even tho its not supercharged, does it make a difference or no? thanks