Caution: Refer to Exhaust Service Caution in the Preface section.

Caution: Refer to Battery Disconnect Caution in the Preface section.

1. Disconnect the negative battery cable.
2. Remove the front suspension support brace. Refer to Front Suspension Support Brace Replacement in Front Suspension.
3. Remove the fuel rail cover.



4. Lift the locking lever on the mass air flow (MAF) sensor, then disconnect the MAF sensor electrical connector (1).
5. Lift the locking lever on the intake air temperature (IAT) sensor, then disconnect the IAT sensor electrical connector (2).
6. Loosen 2 intake duct clamps (3), then remove the duct.
7. Relieve the fuel pressure. Refer to Fuel Pressure Relief in Engine Controls.
8. Remove the oil level indicator and tube. Refer to Oil Level Indicator and Tube Replacement in Engine Mechanical.
9. Plug the opening of the oil level indicator tube to prevent entry of foreign matter.
10. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

Important: Use caution not to damage the oxygen sensors while removing the exhaust manifolds.

11. Remove the exhaust manifold to exhaust pipe flange nuts.
12. Lower the vehicle, then remove the spark plugs. Refer to Spark Plug Replacement in Engine Controls.



13. Progressively loosen, then remove the exhaust manifold bolts (1), working from the outside to center.
14. Remove the exhaust manifold and gasket from the cylinder head.



15. If equipped, remove the heat shield retaining bolts (1) and the heat shield from the exhaust manifold.

Important: Tighten the exhaust manifold bolts as specified in the service procedure. Improperly installed and/or leaking exhaust manifold gaskets may effect vehicle emissions and/or On-Board Diagnostics (OBD) II system performance.

1. If removed, position the heat shield to the exhaust manifold.

Notice: Refer to Fastener Notice in the Preface section.




2. Install the heat shield to exhaust manifold bolts.

Tighten
Tighten the heat shield to the exhaust manifold bolts to 9 N·m (80 lb in).




3. Position the exhaust manifold and new gasket to the cylinder head.

Important: Do not apply thread sealant to the first 3 threads of the exhaust manifold bolts.

4. Apply a 5 mm (0.2 in) wide band of threadlocker GM P/N 12345493 (Canadian P/N 10953488), or equivalent, to the threads of the exhaust manifold bolts.
5. Progressively torque the exhaust manifold bolts from the center to the outsides using 2 steps.

Tighten

1. Tighten the exhaust manifold bolts, first pass to 15 N·m (11 lb ft).
2. Tighten the exhaust manifold bolts, second pass to 25 N·m (18 lb ft).
6. Bend over the exposed edge of the exhaust manifold gasket at the front of the cylinder head.
7. Install the spark plugs. Refer to Spark Plug Replacement in Engine Controls.
8. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
9. Install the exhaust manifold to exhaust pipe flange nuts.

Tighten
Tighten the exhaust manifold to exhaust pipe flange nuts to 25 N·m (18 lb ft).

10. Lower the vehicle.



11. Position the intake duct then install 2 intake duct clamps (3).
12. Connect the (IAT) sensor electrical connector (2).
13. Connect the (MAF) sensor electrical connector (1).
14. Install the fuel rail cover.
15. Install the front suspension support brace. Refer to Front Suspension Support Brace Replacement in Front Suspension.

Caution: Refer to Exhaust Service Caution in the Preface section.

Caution: Refer to Battery Disconnect Caution in the Preface section.

16. Connect the negative battery cable.