Problems, no, but its not very impressive even on three, mostly increases the EGT without much else happening. Seat of the pants tells me that at all levels the increase is very narrow, nothing below 2200RPM, peaks at 2800.
You can't tow with it on 3, and on 2 it gets hot quickly and actually slows you down because of the need to back out due to high EGT.
Pressure only on a 600 just doesn't cut it, mine is for sale. Without injectors I think its a waste.
I tried the Bully Dog Power Pup, wow, ordered one, nicer bunch of guys up there when you call them too. Much better power on program 2 than the EZ has on level three and I can tow with it. Temps are much lower, torque improvement is much better at low RPM, where the EZ just doesn't appear to exist.
The EZ on a 600 just doesn't compare to the EZ on an '03 HO. My two equally equipped trucks, with the '03 running 35" tires and the '04. 5 being a dually, both on the top level, the '03 spanks the '04. 5 flat out and up the hills, rolling or from a dead stop, and thats with my wife driving the '03.

The Power Pup on program three... .
