Gas Cap Issue

[mjschocken]

I have a 2016 Jayco Redhawk on a Ford F450 chassis. I've had issues with the gas cap where the dashboard icon comes on indicating it's not tight. Eventually the check engine light comes on. I've had it over to Ford three times now. They've done diagnostics and can't find any issues. The last time, they replaced the gas cap. It seemed okay for a while but I have the issue again today. Interestingly, I had the issue with my Jeep the other day and put the cap on again by pressing and turning the cap until it clicks a few times. Icon light went off. So I can't help but think maybe it's me with the Redhawk's gas cap. I mean, it's not rocket science, just seat and turn until it clicks, right? Anybody have similar issue or suggestions?

[luvlabs]

If you are putting the gas cap back on properly (turn until it is tight, then a couple of clicks) and are still getting the Ck Engine Light, then you or someone needs to look further at the evaporative control system. It could be a loose hose or even a bad charcoal canister.

[masdixdragon]

May also want to check the fill tube to the gas tank and make sure both ends are OK....had a vehicle once that would give intermittent problems on the same code

[Bob_C]

Over filling the tank can cause the canister to get saturated.......

[Houdoxi71]

As suggested, it's an evap system code. The 'go to' dealer fix is clear it and sell you the most obvious part 'we've got tons of gas caps in stock, common problem'!

There are probably 10-20 evap codes that start with the same prefix.

In my experience, most dealers are part swappers.

I chased this issue on one of my Audis for a while, it was a broken reed valve in the charcoal canister, that wouldn't pass the pre-start pressure hold test as the valve could never close. I was informed it was the gas cap by everyone, it still has the factory gas cap installed to this day and no more issues.

The fact that it repeats itself on your other vehicles might be a clue, no offense.

I'd listen to Bob's advice.