Help - P0442 Code Evap system small leak

[Shade Tree Welder]

So I have had this code for awhile now, no other codes. What are the easy things to check first?

Just looking for some advice to minimize any busted knuckles, as there is no room to work on this thing.

TIA,
Ron

 

[peterk9]

Welcome to the Forum Ron.
I don't know how much you have searched but there are many articles on the code and hints as to what to check;
P0442 Evaporative Emission Control System Leak Detected (small leak)
P0442 Evaporative Emission Control System Leak Detected Small Leak
Have you confirmed that the flap in the fuel filler pipe is closing properly?

Peter

 

[1995E]

It’s the purge valve.

 

[peterk9]

Same video plus another can be found in this thread; CODE P0456

Peter

 

[Shade Tree Welder]

Welcome to the Forum Ron.
I don't know how much you have searched but there are many articles on the code and hints as to what to check;
P0442 Evaporative Emission Control System Leak Detected (small leak)
P0442 Evaporative Emission Control System Leak Detected Small Leak
Have you confirmed that the flap in the fuel filler pipe is closing properly?

Peter

Peter Thanks,

I will have time later today to check out the filler pipe to make sure that it is sealing well. Yes I have looked at numerous vids and blogs, trying to research this ******* a bit. I have looked at both the links you posted before.

 

[LukerDooker]

I had this and fuel inlet was fine, purge valve was fine, canister is in cats area and did not check that.
Ltd has capless fuel inlet. but check fuel door -must have snug fit and gasket in good shape.
Actual metal fuel inlet is not a flimsy flap, its real sturdy and not easy to know what its doing-very little room in there and you cant really feel the gas nozzle in the hole.
Did my own reset with OBD 4 or 5 times, each time still came back after a day or two.

B/c i did resets, initial inspection didnt pass this year due to code "emission system not ready".
Drove it 100 miles in varied driving to perform system recalibration and it passed 2 days later, have not seen it come back in 3 months.
-I reset code but did not delete history.
-dealer system did not report "tampering".
-no other codes displayed.
If it happens again 1st thing ill check is purge valve.
Multiple posts on here of spider webs in fuel inlet or gas cap area causing this as fuel doors or inlet cant seal enough.

 

[Shade Tree Welder]

It’s the purge valve.

Already replaced that, hoping for an easy fix. I cleaned around the fuel fill. Blew a lot of dirt out of it and cleaned everything well.

I have the Auto Enginuity computer interface, I purchased the Ford add on so I have "full access" to all the Ford systems. I reset everything yesterday and drove 3 separate trips for over 80 miles today. Dentist, Hair cut and then the Laundromat to wash the sleeping bags, don't fit in the household washer or dryer. Still no check engine light, yet. Fingers crossed.

Thanks for the input!

 

[Shade Tree Welder]

Well my check engine light came back on today... grrrrrrr... I have to leave tomorrow for a week long business trip. I will have to replace the valve under the car when I get back. Oh well...

Thanks for all the help!

 

[Addam12]

I was getting that irritating "Small Leak" code P0442 (I hope I didn't switch numbers) on my 2012 Ford Explorer XLT 4WD. After having cleaned the gas tank filler flap with some WD-40 and worked it to remove any sticking issues, replacing the purge valve, and the tank valve (that one down under the passenger side near the rear wheel), I couldn't figure what else to do.
Alas, I heard my exhaust had a hole by the flex pipe. I removed the old one and replaced it, using two band clamps with muffler dope to ensure no leaks. Well, it's been over 500 miles and no OBD code. So, if you are getting any leak detection code, keep it simple and check your exhaust for a leak.
Good luck.

 

[dniksich]

I'm working on a friends 2017 Explorer XLT 3.5 trying to get it to pass emissions but can't get the fuel system and evap sensors to be "ready" and I keep getting a pending P0442 small leak detected. One time I got a P0456 very small leak but it's back to 442 now. New cap, purge valve and vent valve and tried a smoke machine numerous times and can't find a leak anywhere. I'm literally going crazy trying to get it fixed. I will be eternally grateful to the person that can give me suggestions on what to try next and hopefully fix it! TIA

Oh, it does have a gas cap as it's been converted by Braunability for wheelchair access and that's what they did when it was new.

 

[Digitalgp]

FWIW I had a similar issue on my '12 Fusion. From the advice of a mechanic I loosened the bolt holding the filler neck in place and adjusted it up slightly and help in place as I retightened. Also found the black plastic bezel with the easy fill/no e85 logo was loose and snapped that back into place. One of those fixed it & haven't had the code come up since. That was about a year ago

 

[peterk9]

I'm working on a friends 2017 Explorer XLT 3.5 trying to get it to pass emissions but can't get the fuel system and evap sensors to be "ready" and I keep getting a pending P0442 small leak detected. One time I got a P0456 very small leak but it's back to 442 now. New cap, purge valve and vent valve and tried a smoke machine numerous times and can't find a leak anywhere. I'm literally going crazy trying to get it fixed. I will be eternally grateful to the person that can give me suggestions on what to try next and hopefully fix it! TIA

Oh, it does have a gas cap as it's been converted by Braunability for wheelchair access and that's what they did when it was new.

Welcome to the Forum.
Your thread was merged with this one. Perhaps it might help.

Peter

 

[dniksich]

Hopefully someone will chime in and give me a idea on what else it could be. I checked 2 more times with smoke and I'm confident there's no leak in the system. How does the ECM know to throw a code for a leak? I'm assuming there's a pressure/vacuum sensor somewhere telling it there is one? And maybe that's bad?

 

[ProjectSHO89]

How does the ECM know to throw a code for a leak?

Pop over to www.motorcraftservice.com and download the OBDII Theory manual for your model year. The test logic for all of the various OBDII processes are explained in it.

 

[abes.shop]

So I have had this code for awhile now, no other codes. What are the easy things to check first?

Just looking for some advice to minimize any busted knuckles, as there is no room to work on this thing.

TIA,
Ron

On my 98 4.0 Sport it was as simple as replacing the oil filler cap.

 

[ProjectSHO89]

On my 98 4.0 Sport it was as simple as replacing the oil filler cap.

Well, he doesn't have a '98 4.0 and besides, the oil filler cap has nothing to do with the evaporation emissions system test failing due to a detected leak. Fuel cap - yes, oil filler cap - nope.

 

[dniksich]

I'm still stumped. Blocked the vent valve since I don't have a scanner that I can use to close it, and filled the system up with smoke again and see nothing and where as far as a leak of any kind. Changed the gas cap for the heck of it and drove it for a few cycles and the code popped up as pending again but this time it's a P0456 very small leak now! Is there a way to "fool" the computer into thinking there's no leak so I can get the damned emission test done? 2 counties in the whole state that still do emission tests and I happen to live in one.

 

[ProjectSHO89]

Is there a way to "fool" the computer into thinking there's no leak so I can get the damned emission test done?

Yeah. Keep the tank filled over the threshhold (see OBDII manual) so that the rest of the monitors run to completion but the evap monitor is prevented from running. The evap monitor requirement to have been completed is waived in most jurisdictions since it's such a PITA to get it to run on many vehicles. Once you get everything else green, go get your test done before the evap tries to run. You could also fool the IAT sensor so the PCM thinks it is too cold.

Once you get past your e-test, the light will assuredly come back on but you're good to go as far as licensing obstacles.

 

[dniksich]

Yeah. Keep the tank filled over the threshhold (see OBDII manual) so that the rest of the monitors run to completion but the evap monitor is prevented from running. The evap monitor requirement to have been completed is waived in most jurisdictions since it's such a PITA to get it to run on many vehicles. Once you get everything else green, go get your test done before the evap tries to run. You could also fool the IAT sensor so the PCM thinks it is too cold.

Once you get past your e-test, the light will assuredly come back on but you're good to go as far as licensing obstacles.

Fool the IAT sensor? What does that do? And how do I do that? Also I just checked smog readiness and see there's 2 tests not completed one evap of course and the other fuel? I got a code a while back P2068 fuel level sensor "b" circuit high? Hasn't come back as pending for quite a while though but maybe that has something to do with the fuel test not completing? I don't know what caused that cause the gauge works fine. The owner is fine with the evap code as long as he can get plates for it.

 

[dniksich]

Anyone know why the fuel system sensor saying it isn't ready? What do I have to do to get it ready? Since it takes a while for Evap tests to complete if I can get the fuel system ready, I can run the vehicle down to get the emissions to pass since I can have 1 monitor "not ready"