Some folks have sent messages asking about my P1502 code problem and if I found a fix for it. I must have forgotten to post it on the forum so here it is just in case you run into the same thing.
I finally gave up on the problem and took it to a P-car mechanic who got down to the car's computer. He was going to send it in to have it checked out, but there was about a 2 week waiting line so he removed the computer from the car and had it in the office until they would call him and tell him to send it in.
In the mean time, a few days later, he decided to put the computer back in and see what would happen. Since it had been without power for a few days the computer should have done a hard reset. He put the computer back in and, voila, everything ran perfectly and it has ever since (over 2 years now I believe).
If you run into the problem try completely unplugging the computer. Make sure you unplug everything, including the ground wire if there is a separate one, and let it sit for a day or two (I'm guessing at the amount of time, maybe someone can fix this if you know how much time is really required).
Hopefully that will take care of the problem...for free!!