Evap and Fuel Filler codes

[jasong_10]

2012 SHO with capless fuel filler

I'm getting an evap leak code and a loose filler cap code. Also getting check fuel filler message on info screen in cabin. Both the purge solenoid and vapor canister solenoid are functioning properly, and smoke test revealed basically nothing. Only smoke leak occurred when filler neck flapper was pushed in slightly/gently.

Order of codes is as follows:
-message in cabin
-fuel filler CEL code
-evap CEL code

I'm thinking it has to be the filler neck . . .

Any thoughts?

 

[rubydist]

In my experience its most likely the fuel "cap" that has a small leak.

 

[jasong_10]

That's what I'm leaning towards too, the little flapper part as it's a capless setup, which means replacing the whole filler neck . . .

 

[jasong_10]

So I replaced the filler neck assembly and cleared the codes. Ran through 3/4 tank of fuel and the "check fuel inlet" came back on. No CEL yet, but the scanner showed the same 455 and 457 evap and fuel filler codes as before . . .

Only thing I noticed was a small plastic clip in the new filler neck assembly



The old neck doesn't have one in it, and neither do my F150 or Explorer capless setups. I removed the clip and cleared the codes just for kicks but I don't think it's going to make a difference as it doesn't look like it was holding the flapper open.

I'm at a loss, anyone fought this battle with a Gen 4 that can chime in?

Any help would be appreciated, thank you.

 

[luigisho]

You check the lines to and from evap charcoal cannister? Did you change the cannister purge valve? The one on my f-150 was pretty cheap. They can seem to work but lose vacuum slowly

 

[jasong_10]

You check the lines to and from evap charcoal cannister? Did you change the cannister purge valve? The one on my f-150 was pretty cheap. They can seem to work but lose vacuum slowly

I'll take a look at the lines. I haven't replaced either of the valves. This may be a dumb question, but would the purge valve losing vacuum cause a "leak" code?

 

[luigisho]

I think so. The only things I can think of are cap or for capless the seal and hoses --from filler neck and to and from cannister and maybe the check valves. Maybe the cannister is an issue but that would be the last thing I looked at I think. You can clear the codes and make sure they are new codes after working on it correct?

 

[jasong_10]

I think so. The only things I can think of are cap or for capless the seal and hoses --from filler neck and to and from cannister and maybe the check valves. Maybe the cannister is an issue but that would be the last thing I looked at I think. You can clear the codes and make sure they are new codes after working on it correct?

Yeah, I cleared the codes after changing out the filler neck, but now that you mention it I didn't pay attention to the status of the codes, pending, current, or permanent, this time. My code reader doesn't clear "permanent" codes, the CEL goes off but if I re-scan the vehicle it still shows that code. So the codes it showed this time could have been in the ECM from the last time. All I know is that it went from no lights/messages at all to the message on the dash, and the evap monitor was not set. I just assumed it would have followed the progression it had before and turn on the CEL shortly there after . . .

 

[luigisho]

I'm not closely familiar with the code clearing procedure but you want to be sure that it isn't already fixed and showing an old code.

 

[jasong_10]

I'm not closely familiar with the code clearing procedure but you want to be sure that it isn't already fixed and showing an old code.

Yeah, I'll be more patient this time and pay more attention if/when I put the reader on it next. It just bugged me when the message popped back onto the message center/dash . . .

 

[Casey388]

I know for the permanent codes, you have to do the following:

A Permanent DTC will be erased one of two ways:​

• After three consecutive confirmed fault-free monitoring cycles. The MIL is extinguished and the Permanent DTC is cleared at the start of the fourth fault-free monitoring cycle.
• After one confirmed fault-free monitoring cycle following a scan tool “clear DTC” request.

A driving cycle must include the following:​

• The OBD monitor must run and determine that fault is no longer present.
• Cumulative time since engine start (or propulsion system active for hybrid vehicles) is greater than 10 minutes.
• Cumulative vehicle operation above 40 km/h (25 MPH) occurs for greater than 5 minutes.
• Continuous operation at idle (i.e., accelerator pedal released by driver and vehicle speed less than 1 km/h or 1 MPH) for greater than 30 seconds.

I was battling the same battle after I replaced my cats on my Explorer Sport and hated waiting for the codes to stop showing up on my reader.

 

[Kevin Curley]

I know for the permanent codes, you have to do the following:

A Permanent DTC will be erased one of two ways:​

• After three consecutive confirmed fault-free monitoring cycles. The MIL is extinguished and the Permanent DTC is cleared at the start of the fourth fault-free monitoring cycle.
• After one confirmed fault-free monitoring cycle following a scan tool “clear DTC” request.

A driving cycle must include the following:​

• The OBD monitor must run and determine that fault is no longer present.
• Cumulative time since engine start (or propulsion system active for hybrid vehicles) is greater than 10 minutes.
• Cumulative vehicle operation above 40 km/h (25 MPH) occurs for greater than 5 minutes.
• Continuous operation at idle (i.e., accelerator pedal released by driver and vehicle speed less than 1 km/h or 1 MPH) for greater than 30 seconds.

I was battling the same battle after I replaced my cats on my Explorer Sport and hated waiting for the codes to stop showing up on my reader.

Just went through a similar issue with my daily driver '13 Focus SE. Got a P0456 code for the evap system, replaced the canister purge valve and the CEL stayed on. Drove it a couple times, light still on. Disconnected the negative terminal on the battery for a good 30 minutes, light still on. Thought I would have to clear it with a code reader so I ordered one online. Kept driving the car while I was waiting for the code reader to arrive which was maybe 4 days and the light went out on its own, just had to wait it out.