boothay

Hey guys, kevin here from good ol' Alabama. Ive been having a problem with my car for the last two weeks, P0442 is a small evap leak code. Ive checked under the car, listened for air leaks under the hood. Erased the code like 3 times, comes back everytime. Tries gas treatments and injector cleaners. No avail, I have a 2010 4.6 and I was wondering have any of you guys had this code pop up? I noticed that sometimes my car starts odd and the exhaust sounds funny at times, not all the time. Weird

SpartaPerformance

Evap leak has nothing to do with fuel treatment. It's a LEAK in the EVAP system. The least expensive thing to try is replace fuel cap, don't remember if the 10's are capless. If capless then you need to go to a shop and have a smoke test done to see where leak is coming from.

petrock

As SpartaPerformance mentioned, its an EVAP leak not an issue with the fuel system.

The most common cause is a loose or damaged gas cap. Unscrew it and make sure the rubber o-ring on it is not damaged or dry-rotted. If it is then replace it. If it isn’t then screw it back on making sure its on good and tight. Then clear the code and see if it comes back.

btw, this code is very common with aftermarket gas caps. They often don’t seal properly.

Good luck...

AMDanBailer

These guys have all pointed you in the right direction. Check the Fuel cap and make sure its sitting correctly, this is definitely the most common cause of the P0442 code!

Please let me know if we can be of any further assistance, but I think this should help you solve the issue!

-Dan

boothay

Thanks guys for replying, the 2010 mustangs dont have a gas cap.

petrock

There is something there sealing the filler neck. Whatever that is on your ride may be leaking. The gas tank is supposed to be under vacuum. This code means that something is not allowing it to make a proper vacuum.

Good luck...

SpartaPerformance

I thought the 10's were cap less. I've seen cap less filler necks crack because people lean on them when filling up but there are a lot of reasons why this would go on. You should have a smoke test done.