The Throttle Position Sensor can get out of adjustment due to wear in the throttle body or due to carbon build up. This will cause the idle timing to advance more than 30 degrees which will cause very high HC and NOx emissions. Conversely, the Throttle Position Sensors can wear out and not properly advance the timing which causes a lack of power and poor fuel economy.
Car Problem Reports
Toyota Camry Throttle Position Sensor Out of Adjustment Due to Wear/Carbon Build-up
Toyota Camry Problem
Visitor, 1997 Toyota Camry, 170,000 mi
not fixed still working on it the mechanic has it. it stays reved up in a high setting. even when you start off from a red light it sounds like am tring to race the person next to me.