1997 Ford Thunderbird V-6

I have a 1997 Ford T-Bird with 47,000 miles and V-6 motor. While driving at approx. 45mph it missed once, then again, then a couple of times then just quit. While turning the motor over, it didn't fire AT ALL, initially. It has a completely full fuel tank, I even added a bottle of HEET to rule out crappy fuel. While checking for a spark at the plug, alone, looking through the windshield and hood hinge gap, it appeared there was no spark but, I couldn't see well. While turning it over with the plug wire disconnected the engine started up. I re-installed the plug and wire and it started and ran fine then shut off. It will start, after many tries, then run fine and shut off. It shuts off just like you turned the key off. No sputtering or anything like that. It goes from running just fine to off, just like someone shut off the spark. The DTC says it was running lean at 43mph. I cleared the code by disconnecting the battery, ran it several times and could not get any other codes to pop up. The check engine light has been on for several weeks. I cleared it and it comes back on after driving the vehicle two or three times. I just assumed an O2 sensor was failing. I am thinking the PCM, the MAF or the Cam Position Sensor. Am I on the right track? And if so, how do I troubleshoot it to the correct component?

Thanks,
Pete

Also..... I have been running 89 octane due to pinging during acceleration, (leads me to the MAF)the night before the car quit I filled up with 87 octane. The car has been running perfect prior to this problem.