2010 MKX Gas Cap Warning Light On - NO CEL (So Far)... What Next?

[BobC63]

Hello All -

FIRST POST; new owner of a 2010 MKX that is in generally very good condition . Have had the vehicle for about 15 days.

This issue has popped up. After about 20 miles of driving (post purchase) the 'Check Gas Cap' light came on.
I have not noticed any other symptoms (runs fine, no gas smell, no leaks, no CEL, etc.) since.

First step, I checked that the cap was on securely (it seemed to be, and it was 'clicking' as normal).
Next, after 2 days of the light still on, I inspected the cap. The O-ring seemed a little suspect, so I bought a new OEM gas cap and installed it (since a replacement cap was a cheap and easy fix attempt...). Light did not go out.

3 days later I filled up the gas tank. Light is still on. I have driven about 75 miles since the fill up.

When I purchased the car, I used an OBD2 scanner while inspecting the vehicle and there were no current codes / pending codes / however, the EVAP showed "Not Ready" (all other indicators showed "Ready"). I have a BMW that I have owned for 8 years, and the EVAP always shows "Not Ready" so I did not think too much of it
As of today, No CEL. I will check using the scanner again to look for pending codes.

QUESTIONS / ADVICE:

1) Should I reset the OBD2 using the scanner to (hopefully) turn off the light (and erase any pending codes, if there are any) and then wait to see if the light comes back on?

2) Assuming I do #1 above, and the light does come back on... what should I check next? (Purge valve, something else...)

3) Does the 2007 - 2010 MKX have any history of being prone to EVAP issues (failure-prone components, etc.)? I tried Google and YouTube looking for relevant subject matter but could not find much specific to this generation of the MKX (or Ford Edge) regarding EVAP issues...

Thanks in advance for your help and guidance!

 

[11MarkX]

To answer your questions. My opinion:
1) Yes
2) Check the steel flap in fuel pipe is fully closed. If not, try to lubricate it.
3) No

 

[BobC63]

Checked and there is no flap. I'm thinking that the flap only exists on the "capless" fuel filler vehicles.

 

[BobC63]

UPDATE:

Loose cap light went off on it's own, and I thought I was in the clear...
Next day the CEL came on. Code PO455 'Large EVAP Leak / No Flow'.
Cleared the code - I always do that once; to verify a recurring issue exists (assuming CEL returns).
2 days later, the "Check Gas Cap" light returned.
Did some reading and saw that the next most common EVAP issue is the purge valve.
Bought a new purge valve and installed it (pretty easy).
Cleared the light and drove for about 200 miles until CEL returned. Same PO455.

So far I have replaced the Gas Cap and the purge valve. No impact on resolving the issue.

Everything else I have read says the next steps are more involved; things like smoke-testing the entire EVAP system, and inspecting / testing solenoids, charcoal canister, various vacuum and hard lines, and the fuel tank pressure sensor... all items that are located under the vehicle and difficult to access without a lift.

So... I think my next move is to bring the car in to... (gulp) my local Ford / Lincoln dealer.
I know I'm going to get hosed, cost-wise... but my thought is that the OEM dealer would have the best chance to actually find and fix the issue 100% the first time around (vs. a normal repair shop). I'd rather pay a bit more for (hopefully) the peace of mind that the first fix is the long-term fix.

Anyone else have any other thoughts / ideas /suggestions before I make that appointment with the stealership..?

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[Linc 24]

Clean the fuel filler neck with sand paper where the o ring seals on the gas cap. See other post on same .