P04DB
Crankcase Ventilation System Disconnected
Generic OBD-II
Common symptoms
What you'll notice
- Check for any disconnected or loose hoses in the crankcase ventilation system
- Inspect the PCV (Positive Crankcase Ventilation) valve for clogging or malfunctioning
- Clean or replace the air filters if they are dirty or clogged
- Inspect the intake manifold for any clogs or blockages.
Common causes
Most likely first
- Crankcase ventilation hose disconnected or cracked
- Faulty crankcase ventilation valve
- Blocked or clogged crankcase ventilation system
- Incorrect installation of the crankcase ventilation system
- Damaged or faulty crankcase ventilation filter
How to diagnose & fix
Work through it in order
- Engine running rough or misfiring
- Loss of power or decreased acceleration
- Increase in fuel consumption
- Smoke emitted from the exhaust
- Strong smell of oil or burning oil odor
Read & clear P04DB yourself
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