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
Geo Prizm Throttle Position Sensor Out of Adjustment Due to Wear/Carbon Build-up
Geo Prizm Problem
Visitor, 1995 Geo Prizm, 107,000 mi
for some unknown reason i have total loss of power even with a full tune up after 40 miles per hour cant maintain speeds on highway slows down going up a slight incline no one can find the issue this could be it