OBD-II code · Powertrain (generic)
P04EC EVAP System Large Leak Detected Fuel Tank Side
Same as P04EA but the leak is large enough that the system cannot build the test pressure or vacuum at all - typically a missing fuel cap, an unseated hose or a torn vapor line on the tank side.
Is it safe to drive with P04EC?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyFuel cap missing or not seated
- PossibleVapor hose pulled off or torn
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
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.2–1.5 h
- Emissions test
- Likely to fail
- Parts involved
- Fuel Cap, Evap Hose Tank Side
Related codes
- P04E9EGR Temperature Sensor D Circuit Intermittent or Erratic
- P04EAEVAP System Small Leak Detected Fuel Tank Side
- P04EBEVAP System Small Leak Detected Fresh Air Side
- 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
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.