Need advise on P0442 code

[harveje]

Good evening,
Been reading thru forum on code and getting different angles on it.
Code sets every week or two and usually will set after an extended 4-6 sec crank time which is unusual, truck usually starts right up. When it happens it will turn over 4-6 sec before deciding to run, usually no sputter or stumbling after it starts.. A quick scan shows intake map 6 psi, commanded evap purge 11.8%, evap system vapor pressure 13.50Pa, barometric press 30 psi,
Truck still has erratic idle and shake that's it's had a long time. Gas cap is tight, and no other coded set or pending. Weird thing is my 04 avalanche has the P0 mass leak code that I'm chasing too....
Go finger

Thanks for the help

 

[JennaBear]

Have you checked your gas cap? Might be faulty.

 

[harveje]

did not see any tears or voids on the O ring, and the code sets erratically, But that does not mean it's not bad.. I'm starting a list of components and that's the first on the list but I don't want to start throwing parts, yet.
Thanks for the help

 

[QDaddy]

Hate to bring back a dead thread, but I am experiencing the same issues.... extended crank, p0442 code and additionally, I smell gas fumes from the driver rear. What was the fix?

 

[Hydrazi]

Had the same issue. Replaced the gas cap with one I bought on Amazon. It continued. Had a shop replace solenoids, it continued. Took it to dealer.... they replaced the gas cap with an OEM one. And it worked. Dang it. I will never hear the end of it from my wife. LOL

 

[2011SSVHOE]

You Get what you pay for.

 

[ddubdb3]

if you smell fumes its possible your charcoal canister may be cracked from road debris. may be worth getting underneath and just giving your likes and canister a look

 

[KATfishing]

08 Yukon Denali, 115K. Six months ago, P0496 turned on check engine light so dealer replaced purge valve. All was good for a couple of months, then P0442 code turned light on. I purchased a new OEM gas cap off Amazon and I cleared the code with my reader. Then a week or so later, I had a large leak code P0455 and P0499 (vent valve malfunction), so I ordered updated vent valve assembly and jumper harness adapter from Amazon and installed about 1 month ago. Cleared codes again with reader. It took a while for the evap monitor to return to "ready" status. Everything was good for about 10 days after. I checked every day after driving the vehicle and there were no pending or fault codes. Then today, out of the blue, I started up the vehicle and the engine light stayed on. Checked it with reader and P0442 small leak code is back (1 pending, 1 fault). Nothing noticeable in performance. Fuel level is below 1/4 tank. Cap seems tight. I clicked it for good measure. I have not replaced charcoal canister, but I'm just tired of dealing with this and don't want to keep throwing parts at it. Vehicle drives fine. Thinking I will leave the light on for now and see if code clears on its own. So annoying. I know a diagnostic at dealer is probably the next best move, but I don't feel like paying for it right now. Also, I don't live in an area that requires emissions testing. However, I hate knowing something is not right. I welcome all thoughts!

 

[KATfishing]

For the archive, a leaky fuel pump / gasket on top of tank was the reason for the continual emissions leak. Once new pump assembly and gasket was installed, problem gone. No more light / trouble codes.