A faulty Oxygen Sensor is a primary reason for Failure of a Catalytic Converter. Car Manufacturers Recommend Replacement of O2 Sensors at 60,000 miles. If you are purchasing a New Catalytic Converter be sure the Oxygen Sensors are Checked and Operating Correctly!
YUKON WITH 5.3L Y PIPE CONVERTER ASSEMBLY WITH BALL FITTING AT OUTLET NO WELDED FLANGE TEST GROUP 9GMXT05.3380 LEV2 ULEV OR 9GMXT05.3381 LEV2 ULEV CALIFORNIA OR NY APPROVED - CARB COMPLIANT PER CARB REQUIREMENTS THE TEST GROUP SHOWN HERE MUST MATCH THE TEST GROUP OF THE VEHICLE