Throttle Position Sensor and Engine deceleration after alot of stop and go driving

BASSMASTERD

MEMBER
2004 KIA OPTIMA
2.4L
4 CYL
FWD
AUTOMATIC
165,000 MILES

I had my check engine light come on, and went to an auto parts store and had a code reader put on it, and it said my Throttle Position Sensor A Circuit Low Input. This car has been sort of cutting out after a lot of stop and go driving. The Tachometer drops by 600 to 800 rpm's for short periods, then surges back up to speed. Could the Throttle Position Sensor be behind this? If so, where is it located, and how difficult is it to replace myself? Thank You.

1 Reply

CARADIODOC

MECHANIC
33,871 POSTS

The throttle position sensor is mounted on the side of the throttle body assembly. That's what the fresh air tube and throttle cable are attached to. Be aware though, diagnostic fault codes never say to replace parts or that they're bad. They only indicate the circuit or system that needs further diagnosis or the unacceptable operating condition. Especially in this case, there's less than a 50 percent chance the sensor is actually the cause of the problem. It is more common to have a wiring problem related to that sensor. A mechanic would use a scanner to view live data on a test drive, and he can record a few seconds of activity when the problem occurs, then he can review that data slowly later and watch to see what happened. Without that scanner, you can try a new sensor and hope that solves the problem.