Removal Procedure

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Raise and suitably support the vehicle. Refer to LIFTING AND JACKING THE VEHICLE in General Information.
Remove the exhaust manifold pipe nuts.
Lower the vehicle.

Fig 1: Removing Exhaust Manifold Pipe Nuts - Left (4.3L)
Courtesy of GENERAL MOTORS CORP.
Disconnect the spark plug wires from the spark plugs.
Remove the spark plug wire retainer bolts.
Position the wire harness on top of the engine.

Fig 2: Removing Spark Plug Wires & Retainer Bolts - Left (4.3L)
Courtesy of GENERAL MOTORS CORP.
Remove the spark plugs.

Fig 3: Removing Spark Plugs - Left (4.3L)
Courtesy of GENERAL MOTORS CORP.
Disconnect the engine coolant temperature (ECT) sensor electrical connector (5).

Fig 4: Disconnecting Engine Coolant Temperature Sensor Electrical Connector (4.3L)
Courtesy of GENERAL MOTORS CORP.
Remove the exhaust manifold and spark plug wire shields bolts/stud.
Remove the exhaust manifold and plug wire shields.

Fig 5: Removing Exhaust Manifold & Plug Wire Shields - Left (4.3L)
Courtesy of GENERAL MOTORS CORP.
Remove and discard the exhaust manifold gaskets.

Fig 6: Removing Exhaust Manifold Gaskets - Left (4.3L)
Courtesy of GENERAL MOTORS CORP.
Remove the exhaust manifold heat shield bolts and shield, if required.
Clean all gasket mating surfaces.

Fig 7: Removing Exhaust Manifold Heat Shield & Bolts - Left (4.3L)
Courtesy of GENERAL MOTORS CORP.