Check At O2 Sensor

Remove O2 sensor and install Bourroughs Exhaust Backpressure Tester (BT 8515 or BT 8603). Go to step 1).

1. With engine idling at normal operating temperature, observe gauge reading. Compare with specification table (If applicable). The reading should not exceed specification. Increase engine speed to RPM specification and observe gauge. Compare with specification.
2. If one or more readings exceeds psi (kg/cm² ) specification, restricted exhaust is indicated. Inspect entire system for common causes such as collapsed pipe, heat damage or internal muffler failure. If no other cause is found the catalytic converter is suspect and should be replaced.