P0442 Code keeps coming back

tyhuck · May 18, 2012

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!!!

tyhuck · May 21, 2012

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.

KMGZ400 · May 21, 2012

i have the same exact problem on my 2003 silverado. its driving me nuts.

gmtech4 · May 21, 2012

buy alldata for $27/yr ,cant go wrong or do what eva ya want ,good luck

KMGZ400 · May 21, 2012

would you be so kind to inform me what alldata is?

jaredlucky16 · May 21, 2012

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 · May 24, 2012

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.