System Check - Restricted Exhaust

Exhaust Backpressure Gauge Installation:

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

CHECK AT AIR PIPE
(Left and Right Side AIR Pipes)

1. Remove the rubber hose at the exhaust manifold Air Injection Reaction (AIR) pipe check valve. Remove check valve.

2. Connect exhaust backpressure kit (with air adapter) J35314-A as shown in accompanying image.

3. Insert the nipple into the exhaust manifold AIR pipe.

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 three-way catalytic converter is suspected to be restricted and should be replaced using current recommended procedures.