A 4.3l engine requires vehicle support before you can remove the left Exhaust Manifold by first taking off the Exhaust Manifold pipe nuts then lowering the vehicle. Extract each
Spark Plug wire from its Spark Plug before uninstalling the Spark Plug wire retainer bolts which should be placed atop the engine. Next disconnect the engine coolant temperature (ECT) sensor electrical connector while taking out the spark plugs. Start the Exhaust Manifold and Spark Plug wire shield removal by taking off bolts/studs securing both pieces. After that remove both shields while discarding the Exhaust Manifold gaskets. Wait to begin if you need to remove Exhaust Manifold heat shield bolts then discarding the shield while cleaning all gasket-smashing areas. Place the Exhaust Manifold heat shield back onto position while installing its retaining bolts to reach 9 nm torque (80 inch lbs.). Couples of new Exhaust Manifold gaskets should be installed onto the Exhaust Manifold while making sure the gasket tabs maintain contact between the gasket and bolts. The Exhaust Manifold and plug wire shields should be installed while gm p/n 12345493 (Canadian P/N 10953488) or equivalent threadlock material is applied to old Exhaust Manifold bolts/stud threads before tightening to 30 nm (22 ft. Lbs.). Reconnect the ect sensor electrical connector followed by installing the spark plugs which must be tightened to 15 nm (11 ft lbs). Afterward install the wire harness toward the engine then secure the Spark Plug wire retainer bolts at 12 nm (106 inch lbs). Finish the installation by attaching the
Spark Plug Wires to the spark plugs then raising the vehicle to install Exhaust Manifold pipe nuts before tightening them to 50 nm (37 ft. Lbs.) while avoiding vehicle descent.