Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
Catalytic Converter: Testing and Inspection
Fig. 32 Typical exhaust system restriction check. Models w/air injection
EXHAUST SYSTEM RESTRICTION CHECK
MODELS W/AIR INJECTION
1.
Run engine until it reaches normal operating temperature, then stop engine.
2.
Disconnect and remove check valve from air injection tube or manifold.
3.
Connect suitable pressure gauge to nipple from propane enrichment tool J-26911 or equivalent, then insert nipple into injection tube opening, Fig.
32.
4.
Start engine and run at 2500 RPM while observing gauge.
5.
If gauge reading exceeds 2-3/4 psi, inspect entire exhaust system for collapsed pipes, heat distress or possible internal muffler failure.
6.
If all other components are satisfactory, replace catalytic converter.
MODELS LESS AIR INJECTION
1.
Run engine until it reaches normal operating temperature, then stop engine.
2.
Connect suitable vacuum gauge to any convenient port to direct intake manifold vacuum.
3.
Disconnect EGR solenoid electrical connector, if equipped, or reroute hoses as needed to connect EGR valve directly to vacuum source, bypassing
any switches or solenoids.
