W350 1 Ton Pickup 4WD V8-360 5.9L VIN 1 4-bbl (1988)
Catalytic Converter: Testing and Inspection
The exhaust system should be checked for restriction before any components are replaced. Use the following procedures for diagnosis of the exhaust
system:
Check at AIR Pipe
1.
Remove the rubber hose at the exhaust manifold AIR pipe check valve. Remove check valve.
2.
Connect a fuel pump pressure gauge to a hose and nipple from a Propane Enrichment Device.
3.
Insert the nipple into the exhaust manifold AIR pipe.
Check at Oxygen Sensor
1.
Carefully remove O2 sensor with proper removal tool.
2.
Install Exhaust Backpressure Tester in place of 02 sensor.
3.
After completing test described below, be sure to coat threads of 02 sensor with antiseize compound 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 1 and 1/4 psi (8.62 kPa), 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.
