GM Service Manual Online
For 1990-2009 cars only

Condition

Action

Restricted air system

Inspect for a clogged air filter element or restricted air inlet system.

Restricted exhaust system

Inspect for a restricted exhaust.

Leaking exhaust system

Inspect for exhaust manifold leaks.

Poor oil drainage from turbocharger

Inspect for a restricted turbocharger oil drain pipe.

Restricted crankcase ventilation system

Inspect for a restricted crankcase ventilation system.

Worn internal engine components

Inspect for excessive blowby or engine oil consumption.