Camshaft
 

With the comp 200 camshaft do I need to replace my cars computer? Or anything and will my gas milage go to crap?

I have the comp 200 and I did not mess with my computer and my gas mileage is awesome. One I got is from modern for 299bucks.

What would be the best camshaft 4 my 05 neon sxt with simple bolt ons like headers pulley intake and open exhaust without a cat.?

Another question is people say u run pig rich with the afx chip what's the draw back of running that rich..

I would get the comp 200 like I did for my 04 sxt and my sxt has every mod possible and never heard of that on your 2nd question darth might know more on that.

The AFX chip doesn't do...crap. I wouldn't waste the money on it anyways. Buy a MegaSquirt system if you really want to tune your car.