Catalytic Converter: Service and Repair

REMOVAL
1. Loosen clamp and disconnect the muffler/resonator assembly from catalytic converter pipe.





2. Disconnect downstream oxygen sensor electrical connector.





3. Remove catalytic converter to exhaust manifold attaching fasteners.
4. Remove catalytic converter and gasket.

INSPECTION

WARNING: THE NORMAL OPERATING TEMPERATURE OF THE EXHAUST SYSTEM IS VERY HIGH. THEREFORE, NEVER ATTEMPT TO SERVICE ANY PART OF THE EXHAUST SYSTEM UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE TAKEN WHEN WORKING NEAR THE CATALYTIC CONVERTER. THE TEMPERATURE OF THE CONVERTER RISES TO A HIGH LEVEL AFTER A SHORT PERIOD OF ENGINE OPERATION TIME.

Check catalytic converter for a flow restriction. Refer to Exhaust System Restriction Check for procedure.

Visually inspect the catalytic converter element by using a borescope or equivalent. Remove both oxygen sensors and insert borescope. If borescope is not available, remove converter and inspect element using a flashlight. Inspect element for cracked or melted substrate.

NOTE: Before replacing a catalytic converter, determine the root cause of failure. Most catalytic converter failures are caused by air, fuel or ignition problems.

INSTALLATION
1. Position new gasket onto the manifold flange and install catalytic converter. Tighten fasteners to 37 Nm (325 inch lbs.).

NOTE: Be careful not to twist or kink the oxygen sensor wires.

2. Install (if removed) and connect the downstream oxygen sensor.
3. Install the muffler/resonator assembly.