System Check - Restricted Exhaust

Exhaust Backpressure Tester Connection:

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

CHECK AT HEATED OR UNHEATED OXYGEN SENSORS
1. Carefully remove Oxygen Sensor.
2. Install exhaust backpressure tester (BT-8515 or 8603) or equivalent in place of Oxygen Sensor.
3. After completing test described in diagnosis, be sure to coat threads of Oxygen Sensor with anti-seize compound P/N 5613695 or equivalent 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 8.62 kPa (1 1/4 psi), 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 using current recommended procedures.