This Throttle Position Sensor (TPS) was found to be faulty at 150,000 miles. As this was on an older non-diagnostic system, there was no specific code flagged. The sensor voltage was checked while on the vehicle, and resistance readings of the sweeping resistor taken after removal. Results showed the readings were erratic and out of spec. Once disassembled (shown here) it was clear that the metallic traces inside were worn and degraded.