For 1990-2009 cars

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.