Checking The Exhaust System For Restriction

CHECKING EXHAUST RESTRICTION

Special Tools:






Exhaust system restriction can be checked by measuring back pressure.

WARNING: The normal operating temperature of the exhaust system is very high. Therefore, never work around or 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.

1. Disconnect and remove the upstream (before catalytic converter) oxygen sensor. Oxygen Sensor - Removal.
2. Install the Exhaust Back Pressure Fitting Adaptor.
3. Connect a low pressure gauge to the Exhaust Back Pressure Fitting capable of reading the specification in the table below.
4. Apply the park brake and start the engine.
5. With transmission in Park or Neutral, raise engine speed to 2000 RPM. Monitor the pressure. Back pressure should not exceed the specification in the table below.

NOTE: For applications with dual catalytic converters, repeat test on opposite converter using the previous steps.

6. If pressure exceeds maximum limits, inspect exhaust system for restricted component. For further catalytic converter inspection procedures, Testing and Inspection. Replace or repair component(s) as necessary.
EXHAUST BACK PRESSURE LIMITS