Ken, 93 F150 code Z2D1. I installed the chip, was very meticulous about cleaning the contacts. Buttoned it up and started it. The first day, it ran almost exactly like stock, except for some very mild shifting differences. Running 93 octane. I figured I'd give it some time, it'll improve when it "learns" my truck. This morning, truck would not start until I cranked it for several minutes, then it started in the "limp home" mode. I had to get to work so I drove it. It was like pushing a lead block until I got it above 30 mph, then it smoothed out, only to repeat that cycle every time I had to stop at light. I left it running for awhile after parking it and noticed it running extremely rich and stumbling very hard. I finally got it home, and promptly disconnected the battery to try to "reset" the chip. Nothing. What's up?

 

Remove the chip and reclean the connector using acetone or fingernail polish remover. Do the same to the chip connector. Make sure its very tightly held in place. Ugly as it looks, duct tape secures it nicely.