Engine Code P0440

[Mad Chemist]

My 99 Silverado 5.3 4x4 displadyed a engine code P0440 which I know is the EVAP system. I've checked all the usual suspects, gas cap, loose and/or cracked hoses, etc. Any other suggestions as to what to check?

[GM-Tech]

Evap vent valve.

[Mad Chemist]

Evap vent valve.

 

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How do I check that? Anyone have the part number for the evap vent valve?

[ryan632]

Mine did the same thing last year, turned out to be a cracked evap canistar.

Same code as what you are getting

[Norseman]

My 99 Silverado 5.3 4x4 displadyed a engine code P0440 which I know is the EVAP system. I've checked all the usual suspects, gas cap, loose and/or cracked hoses, etc. Any other suggestions as to what to check?

 

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I had the same problem (code P0440) with my 99 z71 just 2 weeks ago. I brought it over to my mechanic and he hooked up to his computer and ran a test on the entire evap system for me (for free, d@mn he is a good guy) turned out to be the evap purge solenoid. US$30.00 for a new purge solenoid and problem gone. He said because they sit on top of the engine heat can take its toll on them.

 

I just gave him a call and he said for you to start with the purge valve solenoid first then move to the vent valve solenoid, then canister, and then the lines. But, he said it would be easier if you just had someone with a good diagnostic machine run an evap test.

 

Good luck man!