OBD-II code · Powertrain (generic)
P04F0 EVAP System High Load Purge Line A Performance
On engines that have a separate high-load purge line - to use boost pressure to pull vapor on turbo applications - the ECU monitors flow when this path is commanded. The flow is below the expected level - the venturi, line, or check valve is restricted, or the line is incorrectly routed.
Is it safe to drive with P04F0?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyLine, venturi or check valve restricted
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 High Load Purge Line A, Evap Purge Venturi, Evap Check Valve
Related codes
- P28C3EVAP System High Load Purge Line B Performance
- P04EDEVAP System Large Leak Detected Fresh Air Side
- P04EEEVAP System Very Small Leak Detected Fuel Tank Side
- P04EFEVAP System Very Small Leak Detected Fresh Air Side
- P04F1EVAP System Purge Line Performance
- P04F2Catalyst Heater Supply Voltage Bank 1
- P04F3Catalyst Heater Supply Voltage Bank 2
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.