hey man, im pretty new to this also, but the first upgrade i made to my 2000 was the exhaust. i bought the flowmaster and i dont really like it. im switching to the bassani bx. also a cold air intake is a good choice. our trucks have the 85mm mass air flow sensor so a nice cheap upgrade is the 90mm off the 01-04 L's. check out
Lightning Force Performance they have a ton of options and the guys are very helpful. some of the best prices too. hope this helps, peace.
