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.
Driveability Concerns Due to Throttle Position Sensor Out of Adjustment on Toyota 4Runner
Average mileage: 186,500 (131,000–225,000)
12 people reported this problem
1994 Toyota 4Runner 190,000 mi, Visitor
over heating and no power
speedometer stops registering, gears slip, over revving and temperary loss of power..