Failed inspection code P0455

[Skeeter51]

My 1999 Ford Explorer failed inspection with error code P0455. The gas cap tested ok. Check engine light is on. Is there a way to test for the exact problem.
Thank You, Ed

 

[gatzdon]

Smoke Test is the proper way to check for leaks. I believe P0455 corresponds to a large leak (hence guidance is to replace the gas cap or inspect for visible damage).

That said. You shouldn't have gone in for emissions test with check engine light on.

If you just want to buy some time, most states will pass your vehicle with 1 OBD test in the "Not Ready" state, many will even pass the older vehicles with 2 tests in the "Not Ready" state.

Don't know if it's too late for this option, and it's up to you what you do with this information.

After clearing the OBD DTC's, to complete the Evap Monitoring Test, the engine MUST go through the following cycle (don't remember how many times)
=Fuel Tank between 25% and 75%
=Outside Temp between 30F and 90F
=Engine off for at least 8 hours (usually overnight)
=Engine warms up without being shut off
=Vehicle driven with light throttle at about 60MPH for about 10 minutes

If any of those conditions are not met, the Evap Monitoring will not complete and will report that it's Not Ready.

 

[Mike65]

My 2000 Ranger had the small leak code & I found the fuel filler tube was rusted out & the rubber hose from the filler tube to the tank was leaking, you might want to check them, also I read a post on here about rust holes in the tank where the fuel fill hose connects to the tank. Here is the link, check post #-7 . https://www.explorerforum.com/forums/showthread.php?t=378832

 

[lobo411]

Considering how old it is, I'd replace the cap anyway. Who knows? I had to replace mine to pass smog last time it was checked, and they installed a POS generic Fram cap. I passed, but the dang thing was so useless as a gas cap that I ended up replacing it anyway with the OEM Motorcraft cap for $13 (Amazon).

So had I pre-emptively replaced the cap, it would have cost me $13. Since I waited, I had to pay $10 for a junk Fram cap at the smog station + $13 for the OEM cap later.

 

[gatzdon]

Considering how old it is, I'd replace the cap anyway. Who knows? I had to replace mine to pass smog last time it was checked, and they installed a POS generic Fram cap. I passed, but the dang thing was so useless as a gas cap that I ended up replacing it anyway with the OEM Motorcraft cap for $13 (Amazon).

So had I pre-emptively replaced the cap, it would have cost me $13. Since I waited, I had to pay $10 for a junk Fram cap at the smog station + $13 for the OEM cap later.

If you see my '00 Explorer with 263,000 miles, you'd probably agree it's not worth spending $13.



That side, it has so many memories, it's still hard to drive it to the junkyard.