How to Replace Throttle Body 88-98 GMC Sierra K1500

Difficulty: Intermediate · About 50 min · Gmc Sierra K1500

Replace the throttle body on a 1988–1998 GMC Sierra K1500, transferring the cables and sensors before reconnecting the intake and checking for leaks or idle problems.

Steps

1. Remove the air intake

   Release the air box cover clips and disconnect the intake temperature and airflow sensor connectors. Free the breather hose and intake fastener, then lift the intake duct out of the way.

2. Disconnect the throttle body

   Open the throttle plate by hand and unclip the throttle and cruise cables. Unplug the throttle position and idle air control sensors, remove the cable bracket, and take out the throttle body bolts.

3. Install the replacement throttle body

   Remove the old gasket and clean the mating surface. Seat the new gasket in its groove, position the throttle body, and tighten its bolts evenly to the vehicle's specification.

4. Reconnect cables, sensors, and intake

   Reinstall the cable bracket and connect both throttle cables, confirming they return freely. Reconnect the sensor plugs, refit the intake duct and breather hose, and secure all clamps and air box clips.

5. Check operation

   Start the engine and confirm the idle settles normally. Inspect the intake joints for air leaks and verify the throttle opens and returns smoothly before driving.

Check your vehicle’s repair manual for exact specifications and fit.