Can anyone tell me what a TPS does, have you replaced one before/why and if it starts to fail, would it cause my 2000 Bird to over fuel and run crap. I have checked the Fuel pressure reg, changed the plugs and air filter, tested the vacuum pipes and drained the tank. Fault code shows 25 blinks which = knock sensor fault, but that has been tested. The FI light keeps coming on even after the loom fix and my bird runs rich. I am totally stumped now HELP?