Catalytic Converter: Service and Repair

REMOVAL
1. Disconnect negative battery cable.
2. Raise vehicle on hoist.





3. Disconnect downstream oxygen sensor electrical connector and remove oxygen sensor.
4. Support exhaust system with jack stand.
5. Remove isolators from exhaust pipe supports.
6. Apply penetrating oil and loosen the band clamps that retain the front converter pipes to the muffler. Separate the muffler from the catalytic converter pipes.
7. Loosen V-Band clamp at manifold to converter connection. Do not reuse V-Band clamp.
8. Remove bolt attaching converter pipe hanger to rear engine support bracket.
9. Remove catalytic converter(s).
10. Remove and discard V-Band clamp.

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.
Visually inspect the catalytic converter element by using a horoscope or equivalent. Remove both oxygen sensors and insert borescope. If horoscope 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. Install a new V-Band clamp over exhaust manifold coupling flange. Install clamp with nut facing downward.
2. Install catalytic converter(s) to exhaust manifold and position V-Band clamp over manifold and converter flanges. Tighten V-Band clamp to 10 Nm (90 inch lbs.).
3. Install catalytic converter pipe hanger bolt to rear engine support bracket. Torque bolt to 47 Nm (35 ft. lbs.).
4. Install exhaust system and exhaust support isolators.
5. Tighten band clamps to 47 Nm (35 ft. lbs.).
6. Install downstream oxygen sensor and tighten to 28 Nm (20 ft. lbs.). Reconnect downstream oxygen sensor connector
7. Lower vehicle.
8. Connect negative battery cable.