I hope you guys can offer me some advice and guidance. I have a f150 2002 5.4L. It was originally a bi fuel truck. When I bought it a few years ago the propane system did not work. I got a new system put in. ( the alt fuel place that put it in is now out of business). I have been having trouble with an O2 sensor which I could not figure out. I brought it to a Fletchers around the corner to have them take a look at it. They really screwed it up. It was undrivable in the gas mode it drove when using propane. I checked the wires and cleaned them up and bought a PCM from Checker/O'Rielly and installed it. I now get the theft light flashing and it does not start although it cranks. I'm guessing it is due to the PATS system. Does anyone know how I can get the system to recognize the keys? or am I screwed and have to bring it to a dealer?
Try a GOOD locksmith some have the equipment to reprogram . Also O'Rielly may have the ability to reflash your PCM alot of parts stores have this service available .
Only go to the dealer as a very last resort .
You need a parameter reset done and as far as I know the dealer is the only place that can do it. You also need as-built data loaded into the PCM. The pats keys are stored in the cluster and the PCM and cluster have to be programmed to each other.