OBD2 Code P0455- Evap Emissions System leak detected- Large leak (Gross leak)

The P0455 code (Evaporative Emissions System Leak Detected- Large Leak) is a very common everyday code and its causes are simple! There is a big ass leak coming from something related to the fuel tank…… That’s it…… So lets take a look at the most common cause of OBD2 Code P0455.

  1. The fuel cap is loose (most of the time)

  2. Fuel cap O-ring is broken or leaking

  3. EVAP Solenoid (Purge valve) is not working correctly

  4. EVAP Canister has a crack in it

  5. EVAP line(s) are broken and or cracked

  6. Vent control valve is stuck open

  7. The fuel tank has a crack in it

  8. Something in the EVAP system has a big hole and leaking somewhere (Line,Valve,Tank,Canister etc.)

  9. The EVAP pressure sensor has failed or has an incorrect reading

If you still cannot find the issue after verifying that all of this list is fine, then using a EVAP smoke machine may be required. You can usually borrow, or rent one from local parts stores for a reasonable fee.

Diagnosing a P0455 on a 2006 Nissan Frontier 4.0 V6

Scan found Code P0455

Checked the gas cap…..Nope…..Good

Attempted actuation of the Vent Control Valve with scan tool, Valve is located on the top of the Charcoal Canister near the Rear Left Wheel…………….. Actuation failed……..

Removed valve from top of Canister and used Power Probe 4 to see if it would work……Nope

Replaced Valve (Part #911-503 (Part number may vary) , erased code and drove vehicle

No further EVAP related codes found.

On Nissan’s, even more specifically Nissan’s from more rust prone areas are much more likely to have issues with the Vent Control Valve and Clogged Vent lines. There are various write-ups and How-to’s covering Modifications to vent lines to prevent future clogging and problems.