GM 12574320
Exhaust Manifold, Passenger Side

Using a brand-new gasket at installation remains essential for Exhaust Manifold service because old gaskets between the Exhaust Manifold and cylinder head could result in leaky seals which affect obd ii diagnostic operations. The technician should use solvent to cleanse both Exhaust Manifold (600) and heat shield (603) before drying the Exhaust Manifold using compressed air. An examination of the Exhaust Manifold gasket surface should check for abrasive marks or major indentations while inspecting heat shield (603) for any loose or damaged sections and exhaust pipe studs for threaded damage. The obd ii system performance can be affected by any Exhaust Manifold cylinder head deck warpage exceeding 0.25 mm (0.01 inch) within the 2 front or 2 rear runners and 0.5 mm (0.02 inch) overall. This will require exhausting manifold replacement if this criteria is not met.

First support the vehicle at a raised position before removing the right Exhaust Manifold pipe nuts from a 4.3l engine. The first step involves lowering the vehicle while you detach the air cleaner outlet duct clamp that connects to the maf/iat sensor. Start the procedure by taking off the positive crankcase ventilation (PCV) hose then the air cleaner adapter nut. Climb the air cleaner outlet duct above the Throttle Body so you can detach it from its position before taking out the oil level indicator tube. The first step is to unfasten Spark Plug Wires while removing the retainer bolt for spark plugs followed by relocating the wire retainer above the engine before taking out the spark plugs. Before installing the Exhaust Manifold and Spark Plug heat shield bolts you need to remove the Exhaust Manifold and Spark Plug heat shield components before discarding Exhaust Manifold gaskets. The procedure requires removal of the Exhaust Manifold heat shield for cleaning of all gasket mating surfaces. The procedure for installation includes fitting the Exhaust Manifold heat shield together with its bolts that need to be tightened to 9 nm (80 inch lbs.). Place new Exhaust Manifold gaskets under the tabs which will guide the bolts before installing the Exhaust Manifold along with its plug wire shields. The threads of Exhaust Manifold bolts require gm p/n 12345493 threadlock gm p/n 12345493 (Canadian P/N 10953488) for the reused fasteners before installation at a torque of 30 nm (22 ft. Lbs.). Following Spark Plug installation, position the retainer to the engine while installing the bolt in a loose condition before attaching each wire. The oil level indicator tube installation requires tightening the Spark Plug wire retainer bolt to 12 nm (106 inch lbs.). The air cleaner outlet duct needs to be positioned downward while aligning its hinge clip with the Throttle Body lip to insert the mounting stud through the hole. After this, fasten both the air cleaner adapter nut and the pcv hose. Screw the air cleaner outlet duct clamp at the maf/iat sensor then lift the vehicle while installing and tightening the right Exhaust Manifold pipe nuts to 50 nm (37 ft. Lbs.).

Next, remove the starter.

Reconnect the spark plug wires, reinstall the fender wheelhouse extension, put the front tire back on, and lower the vehicle.

Tighten them to 15 Nm (11 ft. lbs.).

Connect the spark plug wires to the spark plugs, raise the vehicle, install the exhaust manifold pipe nuts, and tighten them to 50 Nm (37 ft. lbs.) before lowering the vehicle.

Apply threadlock GM P/N 12345493 (Canadian P/N 10953488) to the threads of the exhaust manifold bolts/stud and tighten them to 30 Nm (22 ft. lbs.).

Remove the spark plug wire retainer bolts and position the wire harness on top of the engine.

Loosen the air cleaner outlet duct clamp at the Mass Airflow/Intake Air Temperature (MAF/IAT) sensor.

Raise the vehicle and remove the catalytic converter from the exhaust manifold.

Remove the exhaust manifold to catalytic converter seal and discard it.

First, raise and support the vehicle.

Remove the exhaust manifold bolts, manifold, and gasket, discarding the old gasket.