What types of things can hand held tuners ie. Diablo, SCT...change. Besides fuel curves and timing. Also to what extend can the timing be retarded on an 01

 

A lot depending on year.

Basics include adjusting the rev limiter in both drive and idel, setting the idel in neutral and in gear, setting/removing the top speed limiter, adjusting shift pressure with the tranny, advancing/retarding spark, adjusting the rear gear ratio for gear swaps, reading error/engine codes, and a lot more.