OBD-II code · Powertrain (generic)
P04B4 Refueling Vapor Control Valve Stuck Closed
Same as P04B3 with the valve stuck closed - vapor cannot reach the canister during refueling, vapor escape from the filler is possible.
Is it safe to drive with P04B4?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyValve stuck closed due to seal or debris
- Less likelyCarbon or debris buildup preventing free movement
- Less likelyComponent wear with age - mechanical play
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.8–1.8 h
- Emissions test
- Likely to fail
- Parts involved
- Refueling Vapor Valve
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.