I have a 98 Expy with the way too small 4.6L engine. Ever since I bought the vehicle I have hated that it down shifts on ever small bump in the road. I recently bought a Hypertech EnergyMax 42000 to see if I could change the increase the power slightly or change the shift pattern to prevent this gas drinking downshifting. My problem is when I hooked it up, it ask if I wanted to change the rev limiter + or minus? It also ask the same type of questions of shift rpms. Can some one help decipher this for me?

 

I have a 99 with a 4.6L in it as well and would like to know how the programming tool does to increase performance. Once you get everything set for max performance please let me know the result. My Expy also shifts at the slightest uphill grade and is not much fun on hilly terrian. Good luck.

 

Do not change the rev limiter, but lower the shift RPMs and you should be good. Do not go too low or you might actually end up stalling the engine.