Caution: Natural gas is highly flammable. In order to reduce the risk of fire and personal injury, keep sparks, flames, and smoking materials away from the vehicle while you perform the Compressed Natural Gas (CNG) fuel system service.

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

1. Disconnect the negative battery cable.
2. Disconnect the gas mass sensor/mixture control valve (GMS/MCV) electrical connectors (1).



3. Remove the GMS inlet elbow bolts (5).
4. Loosen the fuel hose clamp at the MCV.
5. Remove the exhaust manifold nuts (3).
6. Remove the intake manifold nuts (2).
7. Remove the GMS/MCV and the bracket from the engine.
8. Remove the GMS/MCV (1) from the bracket (4).
9. If replacing the GMS/MCV, disassemble the rubber isolators.

1. If replacing the GMS/MCV, assemble the rubber isolators.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Install the GMS/MCV (1) to the bracket (4) with the nuts.

Tighten
Tighten the GMS/MCV to bracket nuts to 12 N·m (108 lb in).

3. Install the GMS/MCV and the bracket on the engine.
4. Install the intake manifold nuts (2).

Tighten
Tighten the GMS/MCV bracket nuts at the intake manifold to 9.5 N·m (84 lb in).

5. Install the exhaust manifold nuts (3).

Tighten
Tighten the exhaust manifold nuts to 27 N·m (20 lb ft).

6. Install the fuel hose clamp.

Tighten
Tighten the fuel hose clamp to 2 N·m (18 lb in).

7. Install the GMS inlet elbow bolts (5).

Tighten
Tighten the GMS inlet elbow bolts to 5.4 N·m (48 lb in).




8. Install the GMS/MCV electrical connectors (1).
9. Connect the negative battery cable.

Tighten
Tighten the negative battery terminal to 15 N·m (11 lb ft).