question

quick answer: NO

long answer: define "performance module"... If you mean the $5 "chip" off ebay that will magically gain you 20hp (haha funny), then no. If you mean a replacement computer (also known as an ECU or PCM) such as the Mopar Performance PCM or an AF/x PCM then yes, you'll gain noticable power, but still dont expect to see 20 extra ponies. The Jet "performance module" is crap for 1st Gens, proven to lose power. It doesnt do much at all for the 00-03 neons, doesnt gain or lose power, you're pretty much throwing $300 out the window. But I hear that its acually gaining a slight bit of power on the 04-05 NGC PCM neons, but only like 3-5hp, and I cant confirm that, just rumors.

If you are asking about one of those cheap modules on Ebay here's my 2 cents. I was given the Nitro Box module off of ebay as a gift ($25). I put it on my car because it was given to me by someone I care about. Does it work? No idea. I put it on the morning before I totaled my neon - hey, maybe it works so well that I lost control of my car! Anyway...wish I could tell you that it does or doesn't. The "butt dyno" couldn't tell. You get what you pay for. I plan to upgrade my computer in the near future. Everyone seems to be very pleased with that mod. I hear the "street/strip" module is favored.