My 99 Catera that I've owned since 16,000 miles now has 169,000. I do almost all work myself and have the shop manual. I replaced the cps about 30,000 miles ago and the car has been fine since...until two days ago when it was running fine. I parked it and two hours later it would crank but would not start. I disconnected the MAF sensor, no luck. I checked the fuel pump relay and it is not engaging. At one time today, it actually started a few times and ran fine, then started doing the same thing again for no reason. I am about ready to get under the car and see if the cps wires are melted or messed up. Could it be that I need to replace the sensor again? Anyone have any other ideas? Autozone did scan it and came up with U2105. I've found nothing on here for that but the manual says it's something with the ECM communication with other devices. The transmission light does occasionally come on when it messes up and I need to shut off the ignition to get it to shift properly again...not sure if that would have caused the U2105 code.