System Check - Restricted Exhaust

Restricted Exhaust Check Tool Set-up:

Proper diagnosis for a restricted exhaust system is essential before any components are replaced.


CHECK AT OXYGEN SENSOR (O2S):

1. Carefully remove O2S.

2. Install exhaust backpressure tester (J 35314-A) in place of O2S (see figure).

3. After completing test described below, be sure to coat threads of O2S with anti-seize compound P/N 5613695 or equivalent prior to re-installation

DIAGNOSIS:

1. With the engine idling at normal operating temperature, observe the exhaust system backpressure reading on the gage. Reading should not exceed 8.6 kPa (1.25 psi).

2. Increase engine speed to 2000 RPM and observe gage. Reading should not exceed 20.7 kPa (3 psi).

3. If the backpressure at either speed exceeds specification, a restricted exhaust system is indicated.

4. Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure.

5. If there are no obvious reasons for the excessive backpressure, the catalytic converter is suspected to be restricted and should be replaced using current recommended procedures.