I just bought a 03 gmc 4 days ago and got my edge juice w/attitude monitor. Its stock besides K&n drop in filter so far. My question is stage 4 or 5 seems like it takes forever to shift the gears almost like its slippin really bad or something? The defuel between shifts is off. Seems really bad in the 1-2 gear shift but still long dead shift for the rest of the shifts. Is this normal? Should i check/change tranny fluids? Truck has 90k miles.