Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 687 (ENGINE EXHAUST SYSTEM)REPAIR INSTRUCTIONSEXHAUST MANIFOLD REPLACEMENT - RIGHT (3.8L)REMOVAL PROCEDURE

1999 GMC Forward Control 5.7 R, Automatic

Removal Procedure

1999 GMC Forward Control 5.7 R, AutomaticSECTION Removal Procedure

WARNING: This page is about a different car, the 2003 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

Remove the fuel injector sight shield. Refer to FUEL INJECTOR SIGHT SHIELD REPLACEMENT (L36) or FUEL INJECTOR SIGHT SHIELD REPLACEMENT (L67) in Engine Mechanical - 3.8L.
Remove the exhaust crossover heat shield nuts.
Remove the exhaust crossover heat shield.

Fig 1: Removing Exhaust Crossover Heat Shield
Courtesy of GENERAL MOTORS CORP.
Remove the exhaust crossover pipe bolts from the right exhaust manifold.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

Fig 2: Removing Exhaust Crossover Pipe Bolts From Right Exhaust Manifold
Courtesy of GENERAL MOTORS CORP.
Remove the exhaust manifold pipe stud nuts and the catalytic converter pipe from the right exhaust manifold.

Fig 3: Removing Exhaust Manifold Pipe Stud Nuts And Catalytic Converter Pipe
Courtesy of GENERAL MOTORS CORP.
Remove the exhaust gas recirculation (EGR) valve inlet adapter pipe bolt from the right exhaust manifold.
Lower the vehicle.
Rotate the engine to access the right side of the engine. Refer to ROTATING THE ENGINE FOR SERVICE ACCESS in Engine Mechanical - 3.8L.

Fig 4: Removing Exhaust Gas Recirculation Valve Inlet Adapter Pipe Bolt From Right Exhaust Manifold
Courtesy of GENERAL MOTORS CORP.
Disconnect the heated oxygen (HO2S) sensor electrical connector (4).
Remove the heated oxygen (HO2S) sensor electrical connector (4) from the engine sight shield bracket (1).
Remove the right side spark plugs from cylinders 2, 4 and 6. Refer to SPARK PLUGS in Engine Controls - 3.8L.

Fig 5: Disconnecting Heated Oxygen Sensor Electrical Connector
Courtesy of GENERAL MOTORS CORP.
Remove the right engine lift bracket bolt and the nut.
Remove the right engine lift bracket.

Fig 6: Removing Right Engine Lift Bracket
Courtesy of GENERAL MOTORS CORP.
Remove the fuel injector sight shield bracket nuts.
Remove the fuel injector sight shield bracket.

Fig 7: Removing Fuel Injector Sight Shield Bracket
Courtesy of GENERAL MOTORS CORP.
Remove the right exhaust manifold bolts and the nuts.
Remove the right exhaust manifold.
Remove the right exhaust manifold gasket.

Fig 8: Removing Right Exhaust Manifold And Gasket
Courtesy of GENERAL MOTORS CORP.
Remove the upper right exhaust manifold heat shield.

Fig 9: Removing Upper Right Exhaust Manifold Heat Shield
Courtesy of GENERAL MOTORS CORP.
Remove the lower right exhaust manifold heat shield.
If replacing the right exhaust manifold remove the heated oxygen (HO2S) sensor from the right exhaust manifold. Refer to Heated Oxygen Sensor (HO2S) 1 Replacement in Engine Controls - 3.8L.

Fig 10: Removing Lower Right Exhaust Manifold Heat Shield
Courtesy of GENERAL MOTORS CORP.
Remove the exhaust manifold studs if damaged.
Clean and Inspect the right exhaust manifold. Refer to EXHAUST MANIFOLD CLEANING AND INSPECTION in Engine Mechanical - 3.8L.

Fig 11: Removing Exhaust Manifold Studs
Courtesy of GENERAL MOTORS CORP.