A bad Throttle Position Sensor (TPS) on your 2003 Chevy Malibu will send your vehicle's computer the wrong signal, causing it to upset the air/fuel mixture, spark timing and the Exhaust Gas Recirculation (EGR) system. Fortunately, the TPS is easy to replace. However, the position sensor on your Malibu is not adjustable. Following the correct procedure will prevent TPS damage and engine performance problems.
Detach the negative (black) battery cable using a wrench.
Remove the air cleaner outlet tube, if you have a Malibu with a 2.4L engine model, using a Phillips screwdriver.
Locate the TP sensor on the throttle body.
Unplug the electrical connector from the throttle position sensor.
Unscrew the two retaining bolts from the position sensor using a Phillips screwdriver and remove the sensor from the throttle body.
Make sure the throttle plate is completely closed.
Set the new TPS in front of its mounting base on the throttle body and align the rotary tangs on the back of the sensor with the tang blades on the throttle shaft of the throttle body.
Slide the TP sensor into position on the throttle shaft.
Rotate the TPS counterclockwise until the threaded holes on the throttle body align with the mounting holes on the sensor.
Start the TPS mounting screws by hand and then tighten and torque the screws to 18- to 35-inch lbs. (2 to 4 Nm) using a torque wrench.
Plug the TP sensor electrical connector.
Install the air cleaner outlet tube using the Phillips screwdriver, if you have a Malibu with a 2.4L engine model.
Attach the negative (black) battery cable using the wrench.
