EVAP Code Struggles

[Jrr011]

Hello All,

I purchased the above 2021 Ranger Tremor truck in early May but prior to buying during an overnight test drive the check engine light popped on. I went by the auto parts store and had the code read. I believe it was p0442 (small EVAP leak), definitely was EVAP system related. So, I took the truck back and had the dealership repair the issue before I bought it. They replaced the EVAP Purge Valve and with the check engine light off I finalized the buy. I did notice that the I/M sensors were not ready shortly after purchase so I knew that I would need to complete drive cycles for them to become ready. After a mix of highway, stop & go, etc. they continued to show as “not ready”. Finally after a couple of weeks and about 300 miles the sensors showed ready and the check engine light didnt return.

I drove for about 1,000 miles and over a month before the light randomly reappeared in early June. This time the code was p0455 (large EVAP leak). The dealership said it would take about a week to complete a diagnostic so I opted to try some other fixes. I read that the capless fuel tank system can have issues with debris, etc. so I used the fuel funnel and WD-40 to open and close the flap several times and clean the area. I also used compressed air to hopefully get rid of any debris. I also checked underneath for any notable hose issues, etc. but didn’t see anything major. I put a little tape on a spot where tape was peeling a bit but didn’t really see anything else. After purchasing a code reader to help with diagnosis and checking I/M readiness I reset the light, drove a mix of highway and stop & go after which all the I/M readiness meters reset this time after only about 50 miles and one driving trip. I continued driving for about 4 weeks and 600 miles with no issues before the light returned last week this time with the code p0456 (very small EVAP leak). So I’ve completed the trifecta of EVAP leak codes it seems.

Rather than trying to figure out logistics of not having the truck for a week or more while Ford diagnoses and fixes I decided to get it smoke tested by a mechanic next door to my job for convenience. I figured if it was a small inexpensive issue I would just have him complete the repair. He completed the test per the Ford flow chart. Found no leaks at fittings or connections. Slight intermittent wisp of smoke visible at the gas cap when EVAP system is closed 100% and system is full of smoke. He says the only source where he sees a leak currently possible is the filler neck assembly itself. He said ford instructs that if no leak is evident replace the purge valve so maybe the dealership did smoke test, didn't see a leak and followed that step (I figured they may have just thrown a part at it and cleared the code). So, his conclusion is likely a small leak present at fuel neck assembly and only course of action is to replace that whole thing. Pretty expensive repair as his quote was over $800 and no complete guarantee that would solve the issue. The catch is that I have a certified blue warranty that has about a month left (3 month, 4,000 miles). So common sense is to take advantage of that but there are several questions marks there due to the following-

• The diagnostic takes several days to complete before they can even begin the repair. There is also a deductible ($100 I believe) and they don't know if the repair will be covered until after the diagnostic is complete, if it isn't covered I'll have to pay over $200 just for the diagnostic that they completed.
• I can't find a straight answer on if the EVAP system is covered by the certified blue warranty, seems to be a bit of a gray area. Since it's been an issue since before I purchased I figure with enough haggling I could get them to cover it, but may be a struggle and will be without the truck for at least a week or more.
• Also not sure what they will come up with following their diagnostic and if they could just say that they aren't finding a leak and give me the run around.

Then, yesterday, the check engine light went off on it's own. I did not clear it. I thought that it would only go away after clearing with a scanner but in researching I guess after enough key cycles (since last Tuesday when the CEL came on) and it not detecting the problem it turns off the CEL. I do still see the code on the reader but that may disappear as well with more key cycles unless it detects the problem again.

So, I am at an impasse as to what to do. I'd like to get it fixed but it seems there are no guarantees there and could end up spending time, money and hassle on something that doesn't affect the performance of the truck. I really love everything about the vehicle expect this, haha. Part of me wants to just clear the code and do that periodically as needed. No emissions testing in my county but there will be starting next year. I figure if it's intermittent though I should still be able to pass the test if I get it inspected when codes are clear and I/M is ready. The small wisp the mechanic mentioned was not directly at the capless cap but more behind it in the area of the picture below. Any ideas for an easier fix to try to seal that area other than replacing everything? I figure could also be something with the EVAP leak detection not working correctly because it's so intermittent and has thrown both large and very small leak codes at different times. You may also notice some scratches around the plastic of the capless neck, not sure what happened there and if that is causing this issue. Any ideas definitely appreciated!




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[RangerBill]

I continued driving for about 4 weeks and 600 miles with no issues before the light returned last week this time with the code p0456 (very small EVAP leak). So I’ve completed the trifecta of EVAP leak codes it seems.

If smoke was detected at the cap during the leak test, I would think that that is the issue (leaking seal at the filler tube). Maybe spend more time cleaning the cap for dirt or debris.

Here is the trouble code description from the shop manual:

 

[airline tech]

With the attached pic and various levels of leak codes, I suspect you are on the right track to replace the filler tube assembly.
And the area has been (attempted) to address a repair, those marks are someone's attempt with a pair of slip joint pliers to remove the cap end and repair.

I suspect the reason for varying levels of leak codes is due to every fill up changes the position of the valving (seal) in the fill tube and what ever position it rests at when the pump nozzle is removed.
Although not 100% positive that this is the only issue, logically its the most likely culprit.

The Fill Tube is a 1-Piece Assembly.
Its not hard to replace, I guesstimate 2 hours at most.

Part Number: KB3Z-9034-A - $325.00 (New) or find a salvage part between $40-$150, I recommend (New)

Note: I have not seen one of these apart and more importantly how the cap end is attached to the tube, I just know that it comes as an assembly, so if the previous attempt to repair was able to disassemble the cap - it clearly did not fix the issue.
I am assuming it has some type of plunger seal design in the tube, thus the reason for a (special) funnel to allow for gas can (fills) etc. to reach down far enough to break the seat of the plunger.
Using other posters about funnels and they did not work, it has to be a specific design length / diameter.

Another design - is you have 2 flapper doors (1 external) and (1 Internal) inside the tube
the internal flapper door is hanging open (weak spring) return

 

[Andrew27]

With the evidence from the small amount of smoke and the scratches on the filler neck, replacing the filler neck would be the “best educated guess” in my opinion. I work at a small independent shop and with it being such an intermittent issue with nothing obviously “broken” it makes sense. But it is an expensive gamble. I always ask customers with EVAP codes if they shut their vehicle off when refueling. It sounds like common sense, but you’d be surprised how many times that turns out to be the issue. Just my two cents lol.

 

[Jrr011]

With the attached pic and various levels of leak codes, I suspect you are on the right track to replace the filler tube assembly.
And the area has been (attempted) to address a repair, those marks are someone's attempt with a pair of slip joint pliers to remove the cap end and repair.

I suspect the reason for varying levels of leak codes is due to every fill up changes the position of the valving (seal) in the fill tube and what ever position it rests at when the pump nozzle is removed.
Although not 100% positive that this is the only issue, logically its the most likely culprit.

The Fill Tube is a 1-Piece Assembly.
Its not hard to replace, I guesstimate 2 hours at most.

Part Number: KB3Z-9034-A - $325.00 (New) or find a salvage part between $40-$150, I recommend (New)

Note: I have not seen one of these apart and more importantly how the cap end is attached to the tube, I just know that it comes as an assembly, so if the previous attempt to repair was able to disassemble the cap - it clearly did not fix the issue.
I am assuming it has some type of plunger seal design in the tube, thus the reason for a (special) funnel to allow for gas can (fills) etc. to reach down far enough to break the seat of the plunger.
Using other posters about funnels and they did not work, it has to be a specific design length / diameter.

Another design - is you have 2 flapper doors (1 external) and (1 Internal) inside the tube
the internal flapper door is hanging open (weak spring) return

Thanks so much for the analysis! Makes sense, I couldn't figure out what was up with the scratches. With it being a Tremor with a nice ARB grill guard with lights, etc. I know it's definitely been off-roading a bit so didn't know if that could have something to do with the issue as well as far as maybe knocking something loose.

So would your best guess be that the leak is at this joint below in the photo?

There are two openings to the tank itself, the outside one in my previous photo and then an inner flap a few inches inside of there. I've worked that in er flap with the funnel and wd-40 in case it wasn't closing up normally. It seems to be although it's hard to see.

[/QUOTE]

 

[RangerBill]

Thanks so much for the analysis! Makes sense, I couldn't figure out what was up with the scratches. With it being a Tremor with a nice ARB grill guard with lights, etc. I know it's definitely been off-roading a bit so didn't know if that could have something to do with the issue as well as far as maybe knocking something loose.

So would your best guess be that the leak is at this joint below in the photo?

There are two openings to the tank itself, the outside one in my previous photo and then an inner flap a few inches inside of there. I've worked that in er flap with the funnel and wd-40 in case it wasn't closing up normally. It seems to be although it's hard to see.

[/QUOTE]
I would say the leak is where the smoke test showed leakage. Was the leak at that joint or at the end that shows damage?

 

[Jrr011]

Appreciate it Andrew, exactly what I'm thinking, expensive gamble. Anyone have any insight as to whether the certified blue warranty might cover this? I typically try to steer clear of the dealership but if it would be covered I'd certainly want to take advantage. But if it ends up not being covered or they repair and the light returns after hassling with them I won't be a happy camper, haha. Kind of annoyed that they did not fix it right the first time around.

Funny you mention fuel ups, I always turn off the engine but the first time the code came back on June for the large EVAP leak it was right after I had been to the dealership to get license plates and a key pad installed since they couldn't figure out the code to the one that was on the truck. My salesman gassed it up before giving me the keys back and I noticed that it stayed on the top line of full for a few days, longer than normal. So, I wondered if he may have topped it off and if that was part of the problem.

 

[Jrr011]

I would say the leak is where the smoke test showed leakage. Was the leak at that joint or at the end that shows damage?
[/QUOTE]
They said it was not at the gas flap itself but in the area right behind that, a small wisp of smoke. So would that mean it's probably coming up from that joint area and seeping out there or tough to say? I wondered if I could gorilla tape the area behind the flap there and call it a day but figured the "leak" may be from that joint area and it's just seeping out there but the system would still detect the internal leak if that makes sense.

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