Disconnecting the throttle position sensor usually makes the engine run poorly or go into limp mode. Common symptoms are rough idle, hesitation, reduced power, stalling, poor fuel economy, and a check engine light.

What you may notice

  • The car may start but idle badly or surge.
  • Acceleration can feel weak or inconsistent.
  • The ECU/PCM may use fallback values, so the engine can still run, but not normally.

Why it happens

The TPS tells the engine computer how far the throttle is open. When that signal is missing, the computer can’t meter fuel and timing correctly, so drivability drops and the car may enter a safe or limp mode.

Safety note

Driving with it unplugged is not a good idea except maybe to move the car a very short distance for diagnosis. If you suspect a bad TPS, it’s better to test the sensor or have it scanned rather than keep driving it.