Nope, no codes. The sensor was reading like .37v-.50v when I first started the engine, then just dropped to like .007-.009v when it warmed up....
The O2 sensor is calibrated to output approximately 0.450-0.500 volts at stoich AFR (14.7:1). Leaner mixtures result in more oxygen content in the exhaust system, which will result in the O2 sensor outputting lower voltage (below 0.450 volts). Richer mixtures result in less oxygen content in the exhaust and thus higher voltage output (above 0.500 volts). The computer supplies a voltage bias on the O2 sensor signal wire of about 0.450 volts, and the O2 sensor will either pull down this voltage (when the exhaust is lean) or pull it up (when the exhaust is rich). The reason for the computer supplying a bias voltage is for diagnostic purposes.
(for those wondering; I don't quote from the 'net because I don't know, it's just a heck of a lot easier than pecking it all out on the keyboard!)
Sounds like you're lean when hot (ie: op temp)
Which jives with bucking under high load conditions.....which is just about any serious application of throttle.
AFR problems are always "seen" by the O2 sensor but are far less often caused by it.
Wild guess time: Bad FPR can cause this type of behavior. Fuel pressure static is not the same thing as FP under load....test it first before throwing more parts at it...
