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P0442 Code keeps coming back

tyhuck

By tyhuck
in Ask A GM Technician

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tyhuck Senior Enthusiast

tyhuck

Posted
Posted

I bought the truck used in 2010 and the CEL was on. The dealer said it was either the gas cap or the vent solenoid. They replaced the solenoid with a factory replacement, but cheaped out on the gas cap. Went great until the weather started warming up and then the CEL came back on. I scanned it and pulled a P0442, which I found out was the EVAP code most commonly referred to as the "gas cap code". I have replaced the cap twice, the second time going OEM with a genuine AC Delco cap. Still getting the code and Im sick of clearing it every few days.

 

So, now I am wondering what the simplest fix for this would be. How many hoses are there in the system, and how hard are they to find? Is the canister easily accessed and replaceable? Im pretty handy at maintaining my own vehicle, and with help from you guys, Ive done 99% of the work on the truck since I bought it. But, I know absoutely zip about these types of systems.

 

Please help before I go crazy!!!

gmtech4 Senior Enthusiast

gmtech4

Posted
Posted

you can throw parts at it like ya did with gas caps

 

OR

 

you can take it to get it diagnosed ,im sorry but electrical cannot be fixed without following a diag trouble tree

 

and spending money wisely

tyhuck Senior Enthusiast

tyhuck

Posted
  • Author
Posted

I know what the code is though. Its a small leak somewhere in the system. Thats really why I was to the pointof replacing stuff. Thats all the dealer told me they could do as well.

jaredlucky16 Enthusiast

jaredlucky16

Posted
Posted

Alldata is online service information. For a small leak code your best bet would be to take it in and have it smoke tested to pinpoint where the small leak is. I.e. could be a pin hole in the filler neck or a vent valve that is stuck open. There is also a TSB to relocate the filter and replace the vent valve with an updated part. Hope this helps.

wages999 Enthusiast

wages999

Posted
Posted

My truck was throwing the same code and it kept coming back after the solenoid was replaced. Turned out that there was a broken wire back by the solenoid that causes the same error code to show up because the computer doesn't get a response from the solenoid.

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