The first step in replacing Throttle Position (TP) Sensor is to supply the fuel lines and the throttle position sensor electrical connector. Remove the two screws on the TP sensor, then remove the TP sensor with the O-ring. Installation should involve the fitting of the O-ring onto the TP sensor and installation of the sensor. Engage a thread-locking agent such as Loctite © 262, GM P/N 12345493, (Canadian P/N 10953488) or their equivalent before bolt tightening the TP sensor screws, doing the tightening till a force of 2 N.m equal to 18 lb in. is achieved. Finally, reconnect the throttle position sensor electrical connector, as well as the fuel lines.