Grand Prix V6-3100 3.1L MFI VIN M (1994)
Catalytic Converter: Testing and Inspection
Proper diagnosis for a restricted exhaust system is essential before any components are replaced. The following procedure(s) may be used for diagnosis:
Exhaust System Test at Oxygen Sensor
CHECK AT 02 SENSOR:
1.
Carefully remove O2 sensor.
2.
Install Exhaust Backpressure Tester in place of 02 sensor.
3.
After completing the diagnosis described below, be sure to coat threads of 02 sensor with anti-seize compound prior to re-installation.
DIAGNOSIS:
1.
With the engine at normal operating temperature, and running at 2500 rpm, observe the exhaust system backpressure reading on the gauge.
2.
If the backpressure exceeds 1.25 psi or 8.62 kPa, a restricted exhaust system is indicated.
3.
Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure.
4.
If there are no obvious reasons for the excessive backpressure, a restricted catalytic converter should be suspected, and replaced.
