OBD-II code · Powertrain (generic)
P04FB Crankcase Ventilation Hose Connection Sensor Range or Performance
The sensor that monitors PCV hose connection reports a value within plausible range yet inconsistent with the engine model - signal does not switch when the hose is moved during diagnosis, or shows offset against actual hose state.
Is it safe to drive with P04FB?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor signal offset
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.4–1.2 h
- Emissions test
- Likely to fail
- Parts involved
- Pcv Hose Connection Sensor
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.