I have a 2005 Buick Lesabre Limited with a little over 109k miles on it. I get the check engine light on and when i check for codes, i'm getting P0455 which is for an evap emission system leak [large leak]. this code might be why i'm getting the message on the dash to check a loose gas cap.
I have a new gas cap yet it persists so, on looking for possible causes, i find a video that diagnosed the cause as an evap purge solenoid that is stuck shut.
Does anyone think this might be the cause of the code, if not, are there any working theories for the cause? Because i got a brand new OEM gas cap and i'm still getting this code.
Believe it or not i have a scan tool. one that Scotty recommended that was about 25 bucks on amazon. That's how i ran the codes. though i will need to learn to read live data.
EVAP canister purge valve. Rock Auto - $13.53.
Thank you all for the possibilities as to what the issue could be. I found out it was the EVAP purge solenoid that had gone bad and replaced it. If this code pops up again, i'll definitely look back on this thread to see what might be up.