Ok, I cleared the codes and rechecked later, got code 13 in position 8, again. As I said before, O2 sensor has been replaced, engine harness as well. engine was running rough at stops, and when I put my foot on the gas, there would be some hesitation and then some surging, in neutral, tach would drop to 500 then up to 1500 twice then settle in around 700, but still a little rough. exhaust smells rich. cruise control works fine.

I don't know exactly what you're referring to when you talk about the slack in the throttle cable...is this at the gas pedal or at the throttle body, and what exactly am I looking for?

What are some other common reasons for this to occur? I have a laundry list of potentialities, wondering if some are more probably than others; MAF, OVP, throttle actuator (bad wiring, gunked up), fuel pressure relay, coolant temp sensor, vacuum leak, bad injectors, etc etc.

Thanks, I appreciate all the input.