Trouble Code P0442

[Zachary Lichliter]

Hello all,



Last week I noticed a couple of things new with the Trac...



My Ultra Gauge alerted me to a pending trouble code of P0442...



I did some quick research and saw that the most common issue for this is the fuel cap, and though I didn't see anything new on the cap but I did notice that metal "flapper" (for lack of a better term) that covers the fuel intake line is stuck in the up position...



Am I wrong and this should always be open or does anyone know a way to repair this?



Thanks in advance,



Zachary L.

 

[Travis Stevens]

i had this problem and i took the rubber gasket off and put a hair tie behind it so that it would get a better seal... no codes so far

 

[EddieS'04]

The metal flapper is not nessecary. Mine has been missing for 5yrs.

My moms 2001 grand marquis about as long. Not sure what it is for.

Havent had any codes.

 

[gyates]

I had the same thing happen on my '05. I was able to use a small flathead screwdriver and effectivley release the spring to cause the flap to close. Since I did this I have not had the code re-appear. I know some say the flap is meaningless, and maybe it is, but in my case when the flap was stuck open I, too, was getting the code that you got. Since closing it I have not gotten the code again.

 

[Bob Floyd]

Small leak in evap system many times its just the gas cap not seated or the seal is damaged...

http://www.explorerforum.com/forums/showthread.php?t=330967&highlight=P0442

 

[swshawaii]

Check fuel cap: Displays when the fuel cap may not be properly installed.

Continued driving with this display on may cause the Check Engine warning light to come on.

Fuel cap would normally activate the dash light. (Page 13)

Also check all vent hoses to the EVAP canister and system.

 

[EddieS'04]

gyates, it was a coincidence that your code went away. It was your cap. When it is not the cap. It is somewhere else in the evap unit leaking. Hose ,etc. Mine broke off and fell in the tank. Never a code. My moms has been bent for many years. After 100K miles she got a code. A new cap fixed it.

 

[scott degroot]

A bit of info on the "check fuel cap" light.



An evap leak will not cause this light to come on...sort of. When you fill up with gas the pcm knows this as it checks the fuel level each time the vehicle is started and compares the reading with the value when the vehicle was shut off. When this happens the system runs a quick evap test and if it fails it turns on the check fuel cap light because it thinks that the most likely cause is a loose fuel cap because you just put gas in it. The system really has no way of telling if the cap is bad or loose, it is just an educated guess based on previous information stored in the pcm.