I have definitely saw posts in this site around this subject, but can't seem to find them right this second. General concensus on that post was that PC was not neccessary and those that had run before and after dyno's only gained 2hp after adding the PC (not sure if that was just overall peak HP or what the gains may have been over the entire run...that was being debated in the thread). I've been thinking about the same and have a geat interest in whether or not PC is neccessary. As I said, the debate weighed against it because that is the function of the O2 sensor...as a closed loop system, the engine management is automatically monitored and maintained because of the in-loop sensor. Disabling the sensor takes away the systems ability to compensate for temperature, altitude, air density, other mods, etc...and kills the SDM A,B,C selector. My disclaimer - I'm not an expert. Just repeating what the other thread had going.