I have an 01. 5 HO with DDIII's and a Hot DDUFM. When I add the smarty software (4,6,or 8) everything is great until I turn the DDUFM on (any level). When, at a lower RPM like 1300~1500 in a higher gear, and I give it a little throttle I hear what sounds like LOUD pre-detonation. I dont know if its the injector pump or coming from inside the combustion chamber. Has anyone else noticed this? No codes, and it runs fine with either the smarty and no box or the box and no smarty. Once the rpms are >1800 or so, it doesnt do it.
Jim

Jim