Okay, let's assume that I am running rich, how do I correct? Do I need to dial back the timing? I am running 17* right now on 87oct. I don't think I did an ecu reset when I installed my POP either. Should I do an ECU reset, would that help? Brian M. Cembor excessive soot usually indicates a rich condition. i would be concerned and try to resolve it (i'm anal that way:) ) Ric in Lacey, Wa.