Check Eng. Light already? P0442
 

Car: 2012 2SS Camaro L99 - Auto
Aftermarket AEM COI
Last Fill up: 3/25/12 - 3983 miles - Shell, 91

I just threw a code at 4152 miles,

P0442 EvaporativeEmission Control System Leak Detected (small leak)

I’m, fairly new to "new" car's, still stuck in the 80's era of Camaro's where I could just count the flashes of the check engine light blinking with a paper clip... so any help on what this may relate to would be appreciated, its still under warranty - I only have an AEM intake installed, and wanted to make sure this isn't something that GM will find as the cause the check engine light went off if it needs to be taken in, since i know they're good at that (06' Aveo, they blamed a fuel electrical issue on the after market radio which was put in the car prior to me purchasing it, so wasn't covered)

From my understanding, this should be a fuel system vapor "Small" leak? So maybe me pulling my gas cap off and putting it back on could fix it (unlikely)?

Yup, I bet just re-tightening the gas cap will do it.

May take a couple of drive cycles to drop away. :thumbsup:

I had the same fault @ about 3k miles on my 2012. Gas cap would most likely be a large leak.i had a leaking valve on the charcoal canister covered under warranty no issue.the tech told me he has done a few I bet your is leaking too. I dont have acai but I do have a catch can installed they gave me no issues. Also acai install should not cause a evap leak.

Hey guys I have a 2012 L99 as well with only 4k miles and my check engine light came on as well for P0442. They said it is the vent solenoid and they special ordered it for me and I have to take it back in and get it fixed. We shall see if it works.

really at 3000 miles
 

Same problem with my Camaro. Just turned 3000 miles. Been in to the dealer twice. The first time the replaced the vent solenoid. The second time they did a smoke test and found no issue. Now the light is on again, with the check engine light and they say I have to bring it in again so they can finally call GM's technicians too see if they can figure it out.

Is anyone else having an ongoing issue?

Attachment 433884

Gas caps are usually attributed to a Large (Gross) Evap Leak, as someone stated above. Usually small leaks could be related to a bad hose or a solenoid that isn't opening or closing properly. A technician will be able to use a diagnostic tool to operate all the solenoids within the system to make sure they're activating/responding. Also they may run smoke through the system to check for visible leaks.

EVAP codes are the harder of the common CEL codes to diagnose, in my opinion.

If I'm repeating the comments of others, sorry. A lot of the EVAP codes in GM's that run through my shop are related to a faulty vent solenoid. I've even installed new ones that test bad as well.

I have the same problem on my 2012 SS with 9100 miles. Taking it to the dealer on Monday. Will post the findings.

Mine did this the other day. Went by advance auto, read the code (po442) and cleared them both. Asked the guys inside and they said to check the gas cap. I took it off, double checked it, and retightened it. No light since, but that was only 4 days ago.

It was the vent valve at the rear of the car. They replaced it without removing the rear bumper. It also is running better. with the problem, it ran like it had a slight vacume leak. The low end is stronger and smoother now. They also reprogramed my air bag under a recall.

I wonder if this could be why my car idles like its retarded...

Epic post of the week!

Is this for all Camaro SS? Seem like everyone that posted has one

Lol

I'm actually curious though too. The idle has always stumbled around on my car and I have tried to fix it a few different ways. Maybe this will help it out. It's just as likely to fix it as the rest of the stuff I tried.

Maybe? No doubt, mine is running much better at the low end. Idles much smoother.