The engine is running poorly, with or without TunerPro RT connected. I'm going to jump off the cliff and make the bold assumption, the spark is going negative without TunerPro RT connected.

It's really weird, absolutely nothing in common between the two vehicles, expect both recently had installed Holley Throttle Bodies. Both vehicles ran great for a period of time after the Holley Throttle Bodies were installed, then not!

Nothing in common means: different definition files, and different computer part numbers. The first vehicle had the problem using a bone stock chip. The second vehicle has a custom chip from me, using a G1 adapter.

dave w