OBD-II code · Powertrain (generic)
P04F1 EVAP System Purge Line Performance
A general performance fault on the EVAP purge line - flow does not match the requested rate, without specifying which segment. Usually a partially blocked line, a stuck purge valve, or a leak that decouples flow from valve commands.
Is it safe to drive with P04F1?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyPurge line partially blocked
- PossiblePurge valve responds slowly
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.8–2 h
- Emissions test
- Likely to fail
- Parts involved
- Evap Purge Line, Evap Purge Valve
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.