P0442 EVAP Emission Control system Leak (Small)

[HawaiiRob]

Aloha from Hawaii!
I have a 2002 Ford Explorer Eddie Bauer, and the service engine soon light has been staying on for months. The first time it came on, I took it to the dealer, who charged my $150 to tell me that the light was on because the gas cap was not fully seated.

A month later when the light came on a gain, I decided to get my own OBDII code reader & checked it myself. It cmae back with the P0442 description in the title.
This sounds like the same thing again (gas cap)...

The cap itself looks fine , & seems to be seated tightly....should I look at replacing that sensor?

Besides the error, the truck runs great (besides the horribe gas mileage).

Thanks for any input!

Rob

 

[rwenzing]

By law, OBDII must run a monitor that can detect even very small leaks in the evaporative emissions system. It uses the engine to apply a light vacuum to the tank, canister and hoses and then monitors a pressure transducer to measure the rate at which the vacuum bleeds off. The smallest leaks can be difficult to pinpoint, so dealers may use a pressurized smoke generator for diagnosis.

 

[HawaiiRob]

Thanks Bob,
...since it doesn't seem to affect the performance, it doesn't seem worth it to spend $$ at the dealership having them test it...

Is this a safety issue?

Thanks,

Rob

 

[muzzymaniac]

I went through this with my old Blazer. I had the same thing for about a year and a half. I pulled the charcoal canister and the canister purge solenoid and put my air compressor to them. I was stuck needing an inspection and then selling the truck so I wanted cheap. Decent sized puffs of dirt came out of both. I was surprised. Anyway, I put everything back together and pulled the battery cable for a while. The light was out and stayed out. I drove it for 3 more weeks with no light and then I sold it. The alternative was to have a mechanic smoke it. I figure that the solenoid had dirt in it keeping it from sealing all the way. My truck was a little older so it was probably a little dirtier. I'm not sure if the Ex's have these same parts or if they operate the same - I've only had mine for a while so I'm still learning about it. Might be work the effort.

 

[MountaineerGreen]

I have had this code on my 01 for months, can't shake it- it has morphed into a P0455, large evap leak I have disconnected all connections I could find, lubricated the O rings, cleaned the canister, replaced the canister purge valve, still can't get it stopped. Very annoying, I just can't get myself to pony up the cash to get the dealer to find the leak.

 

[muzzymaniac]

I have had this code on my 01 for months, can't shake it- it has morphed into a P0455, large evap leak I have disconnected all connections I could find, lubricated the O rings, cleaned the canister, replaced the canister purge valve, still can't get it stopped. Very annoying, I just can't get myself to pony up the cash to get the dealer to find the leak.

Call around to some local mechanics and see if they have smoke machines. Much cheaper than the dealer. I guess it only takes a few minutes to test.

 

[MountaineerGreen]

I live in a very rural area- its all good ole boy shops other than the dealer.

 

[2000XLT4X4]

My 2000 Explorer has had the small evap leak for the past 3 months. I bought a Actron code scanner/reader and cleared the fault, but it came back two days later. My truck has had a gas odor back near the gasfill. I decided to install a new gas cap, cleared the code again. About a week later, same issue.
Next step may be to replace the filler neck. Looks like a liner around the neck opening that has some hairline cracks in it. Worth a shot.
Bill

 

[MountaineerGreen]

Odd that you updated this today- I got a P0442 again today I have a buddy at the dealership, plan to do the smoke test one day after hours.