MotorBitP0455: EVAP System Leak Detected (Gross Leak / No Flow)
A large EVAP leak. Missing gas cap is the classic cause.
Educational OBD2 information. Confirm on your vehicle with a scan tool. MotorBit can read this code, freeze frame, and live data over an ELM327 adapter.
What P0455 means
The PCM could not build or hold EVAP vacuum/pressure, indicating a large leak.
Why the check engine light comes on
Unmetered fuel vapor is leaving the tank system, so the emissions lamp is set.
Common causes
- Gas cap left off
- Disconnected EVAP line
- Split hose
- Failed vent valve stuck open
Typical symptoms
- MIL
- Possible fuel smell
What to do next
- Check the cap first.
- Visually inspect lines at the tank and engine bay.
- Use MotorBit to see if other EVAP codes are stored.
How MotorBit helps
Open MotorBit, connect your ELM327, and read P0455 with freeze frame (RPM, load, temperature, speed at the moment the fault set). Then watch live PIDs and fuel trims instead of replacing parts by guesswork. When the repair is verified, clear the code and re-check monitors.
Download MotorBit on the App Store
FAQ
Is P0455 serious?
Severity is listed as low on this page. Misfire, crank/cam, and communication codes deserve faster attention than a tiny EVAP leak.
Will disconnecting the battery clear P0455?
It may hide the lamp temporarily, but the fault usually returns and you lose freeze-frame evidence. Scan first, then clear after the repair.
Can MotorBit clear P0455?
Yes, after you understand the cause. Clearing without a repair is how the light comes back on the next drive cycle.