Signs of a Poor Throttle Position Sensor

• A throttle position sensor is a device in automobiles that helps the electronic control module determine the throttle's position. It helps the module manage fuel flow into the engine and regulate proper combustion. When this component fails, it affects engine performance and causes problems with acceleration and maintaining speed. If a throttle position sensor isn't replaced, it will have a damage ripple effect on other engine components.

Hesitation

• According to the automotive repair website AA1 Car, engine hesitation and stumble are "classic symptoms" of a bad throttle position sensor. The issues usually appear during acceleration and results from a fuel mixture with too much air to power combustion. This issues eventually evens out when the oxygen sensor corrects the airflow, though not enough to keep the engine from suffering persistent hesitation and stumble.

Fuel Issues

• The lack of adequate fuel caused by a malfunctioning throttle position sensor will affect fuel economy. A driver often will find himself or herself attempting to push more fuel into the engine by aggressively stepping on the gas pedal. This puts excessive fuel in the engine. Excess fuel can foul the spark plugs and other engine components.

Wide Open Throttle

• A burned-out throttle position sensor will cause a vehicle's on-board computer system to read the throttle as wide open all the time. This results in a rich fuel mixture, meaning that too much fuel is entering the engine without an appropriate ratio of air. Fuel economy is affected, and a rich fuel mixture also raises vehicle emissions, which might cause the vehicle's on-board computer to illuminate the "check engine" light.