I am started getting this code Saturday while on the way back from visiting my mom in West, Tx. I had the local autozone use their reader and get the P0442 code so I pulled the gas cap off and put it back on and made sure it clicked a few times. Normally it takes just a few minutes and the light goes off it is the gas cap. Got all the way back home and the lights still on, same code, so I replace the gas cap with a new one. The SES light is still on, any ideas what my problem is now and how to fix it?

Here is the information on the code:

A code P0442 most likely means 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)
* A small leak/hole in a fuel vapor hose/tube
* Other small leak in EVAP system
* Faulty vent o-ring seal

This is on my 04 Sierra, completely stock other than the intake and vette servo

 

check the gas cap seal, may need a new one even though u tryed to tighten it. tighten all ur hose fittings, check compression, and pulgs.... what we do at the dealership?

 

i replaced the gas cap......

 

i have the same code, only will come on about 2 times a month. seems to be at random..

 

Mine use to give me a message saying "tighten fuel cap" i then bought a new one and nothing still was on i got a buddy a the dealer ship to clear it so far it has not came on.

 

check your hoses, or could even be your canaster????

 

maybe ill have a local shop do a smoke test

 

I'll guess it's along the lines of 1 of the 2 things in red. This has been on here before, but I never noticed til I had same problem.

Now that this occurred to me, I may be in the clear, cause I cleared the PO442. It wasn't allowing me to pump gas. Did that happen to you, where it shuts off pump?

I had been fighting this for 1-1 1/2 mo. I cleared it & it improved. I'll find out today if it's still an issue if I get gas. IIRC, it's an evap emissions vent solenoid.

 

The light will stay on until the EVAP monitor runs again and the system passes the test, there are a bunch of parameters that have to be met for the EVAP monitor to run. I currently have a check engine light with a code P0446 due to a bad vent valve that I haven't had the dough to replace. Every so often the light will go off for a day or two, until the monitor runs again and the system fails. Have the code cleared and see if it comes back...

 

now that you mention that i was having problems getting gas on Thursday, how much was the vent solenoid?

i also got gas sunday night and did not have any problems, different gas station though