Catalytic Converter: Service and Repair

Catalytic Converter

Material:

Removal and Installation

1. WARNING: If equipped with fire suppression system, depower the system. For important safety warnings and procedures, refer to Fire Suppression System.

With the vehicle in NEUTRAL, position it on a hoist.

2. WARNING: The electrical power to the air suspension system must be turned off prior to hoisting, jacking or towing an air suspension vehicle. Failure to do so can result in unexpected inflation or deflation of the air springs, which can result in shifting of the vehicle during these operations.

If equipped, turn the air suspension switch OFF.
3. Disconnect the heated oxygen sensor (HO2S) and catalyst monitor sensor (CMS) electrical connector.
4. Remove and discard the 2 catalytic converter-to-exhaust manifold nuts.
^ To install, tighten to 48 Nm (35 ft. lbs.).
5. Remove the catalytic converter-to-outlet pipe bolts, the flag nuts and the damper, then remove the catalytic converter.
^ Discard the bolts, the flag nuts and the gasket.
^ To install, tighten to 40 Nm (30 ft. lbs.).

6. NOTE: Apply a thin coat of anti-seize lubricant to the threads of the sensors before installation.

If installing a new catalytic converter, remove the HO2S and CMS.
^ To install, tighten to 41 Nm (30 ft. lbs.).

7. NOTE: Clean the mating surfaces of the exhaust manifold, the outlet pipe and the catalytic converter.

NOTE: Always install new exhaust system fasteners and gaskets.

NOTE: Do not tighten the fasteners until all components are assembled. Make sure to tighten all fasteners beginning at the front of the vehicle.

NOTE: To correctly seat the converter, alternately tighten the exhaust manifold-to-catalytic converter nuts to specification.

Alternately tighten the catalytic converter-to-inlet pipe bolts to specification to draw the flanges together evenly.
To install, reverse the removal procedure.

8. WARNING: If equipped with fire suppression system, repower the system. For important safety warnings and procedures, refer to Fire Suppression System.

If equipped with fire suppression system, repower the system.