Q: The throttle position sensor has been replaced three times on a 2003 Buick lesabre. What is causing it to go bad?

Within conventional throttle position sensors there are metal contacts that sweep across a printed resistor board. Repetitive motion and vehicle vibration can cause these contacts to wear, over time, eventually causing sensor malfunction. If you are sure that the TPS itself, and not something else such as a loose connector, has failed in other like "repetitive part failure" scenarios, the best thing to do is buy the OEM GM part from the dealer. You should test the TPS and replace if indicated. If you want these steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a TPS sensor diagnostic/inspection and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.