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Aloha guys I’m having issue with this P0455 code in my 03sonoma truck I know this code has to deal with the evap system leak at first I changed the gas cap at first and that didn’t help and after I changed the vent valve solenoid and the check engine light still came back on what else do I need to change to get rid off this problem? Please help!
thanks guys Aloha.
 

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Aloha guys I’m having issue with this P0455 code in my 03sonoma truck I know this code has to deal with the evap system leak at first I changed the gas cap at first and that didn’t help and after I changed the vent valve solenoid and the check engine light still came back on what else do I need to change to get rid off this problem? Please help!
thanks guys Aloha.
For this Code,
Causes A Code P0455 As You Most Likely Know it Means that One or More of the Following has Happened:
...A Loose or Improperly Affixed Gas Cap
...A Non-Conforming Gas Cap (i.e. Not Factory/Original Brand)
...Other Leak or Damaged Piece in EVAP System

Possible Solutions with a Code P0455, and the Most Common Repair is to...Remove-n-Reinstall the Gas Cap.....With That, When You Replaced the Gas Cap, Did You Install a New Factory/OEM Gas Cap??....

Also, Inspect the Entire EVAP System for Cuts/Holes in Tubes/Hoses (You May Hear a Vacuum Noise or Smell Fuel), Repair/Replace if Necessary.
 

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Could also be the purge valve by the engine leaking as well. Best way to check for leaks is to take the valve out and see if you can blow through it. The purge valve with no power should be closed and not allow any air to pass through it. With power put to it, it should open and allow air to pass through. The vent valve by the tank I believe is the opposite, no power you should be able to blow through, with power you shouldn't. Could be really anything to do with and lines or hoses that connect to the fuel tank or filler neck as well.
 

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Discussion Starter #4
For this Code,
Causes A Code P0455 As You Most Likely Know it Means that One or More of the Following has Happened:
...A Loose or Improperly Affixed Gas Cap
...A Non-Conforming Gas Cap (i.e. Not Factory/Original Brand)
...Other Leak or Damaged Piece in EVAP System

Possible Solutions with a Code P0455, and the Most Common Repair is to...Remove-n-Reinstall the Gas Cap.....With That, When You Replaced the Gas Cap, Did You Install a New Factory/OEM Gas Cap??....


Also, Inspect the Entire EVAP System for Cuts/Holes in Tubes/Hoses (You May Hear a Vacuum Noise or Smell Fuel), Repair/Replace if Necessary.
Hey guys sorry for such a late reply but yes i did put a new gas cap twice I also changed the vent valve and purge valve so what’s left is the charcoal cannister the cel is still coming on so idk I’m thinking of doing smoke test so I can be precise on where the leak is coming from
 

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Discussion Starter #5
Could also be the purge valve by the engine leaking as well. Best way to check for leaks is to take the valve out and see if you can blow through it. The purge valve with no power should be closed and not allow any air to pass through it. With power put to it, it should open and allow air to pass through. The vent valve by the tank I believe is the opposite, no power you should be able to blow through, with power you shouldn't. Could be really anything to do with and lines or hoses that connect to the fuel tank or filler neck as well.
Yeah I just replaced the purge valve and vent valve and still the cel came on? I really don’t want to keep guessing and Change parts I’m thinking of just doing a smoke test so I can where this leak is coming from
 

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At this point, yes you would be better of smoking the system. It sounds like there may be a hose leak somewhere. Any obvious rot visible on the fuel tanks filler neck?
 
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