Exhaust Smoke

Check for cooling system malfunction (cylinder head or intake manifold gasket leak).
Check for fuel injector malfunction.
Check for fuel pressure regulator malfunction.
Check for fuel pulsation damper malfunction.
Check for fuel pump malfunction.
Check for intake air system leak.
Check for restricted air filter.
Check for spark plug malfunction.
Check for spark plug wire malfunction.
Check for PCV system malfunction.
Check for restricted or plugged fuel lines.
Check for worn engine parts.