P0442: Evaporative Emission Control System Leak Detected (small leak)

[floridaoranges]

Has anybody gotten this code before and figured out what causes it? vacuum leak or something?

 

[atomicjoe23]

I just got this code myself yesterday morning. . .and then this morning the engine had a few misses when accelerating uphill. On the way home today it was missing REALLY bad until I got on the freeway, then by the time it got home everything seemed fine. . .

. . .I'll post up if I figure something out.

Any luck figuring this out yourself?

 

[okietheranger]

I just got this code myself yesterday morning. . .and then this morning the engine had a few misses when accelerating uphill. On the way home today it was missing REALLY bad until I got on the freeway, then by the time it got home everything seemed fine. . .

. . .I'll post up if I figure something out.

Any luck figuring this out yourself?

From what I know and I could be wrong the evaporate system is under a vacuum and when the system can't hold constant vacuum it will set the code. The cause could be Many things left off gas cap. Filler hose has a leak or the pump assembly o ring leaking or the check valve were the evaporate return line goes to the back to the tank ( were mine was leaking the line is plastic and has a little 1 and a half rubber piece connecting to the check valve mine had a slice In it) hope that helps.

 

[yodaman1151]

Most common reason is loose gas cap or bad o ring on the cap. Could also be cracked/loose hoses on the evap system. When I worked at Autozone probably 95% of codes we pulled were that or the one for a large leak. I told people to put a little vasoline on the o ring to try to make a better seal. I was told the computer only pulls a vacuum on the system between 1/4 and 3/4 tank of gas so you could just keep it full or empty ha ha. You can reset the light to see if you fixed the issue by just pulling your batt. Cable for a few minutes.

 

[Jack Schmidt]

Reviving this thread only because its title is a good search term.
I get a P0442 only when I load the engine. If I drive around normally, no code. Does this symptom narrow down the cause?

 

[Kira]

What year 4.0l? Check the PCV system. It's a potential source for a huge vacuum leak.
Don't forget smoke testing.

 

[rubydist]

These trucks are getting old enough now that vacuum lines can be developing leaks from cracks. I had an 06 Mustang that would display that code maybe once a month, but it was so seldom that I never was able to chase it down.

 

[Jack Schmidt]

What year 4.0l? Check the PCV system. It's a potential source for a huge vacuum leak.
Don't forget smoke testing.

Year is 2003. 145k miles. Good idea to check PCV as well. I don't see any relevant PCV trouble codes in the trouble code list ( https://www.therangerstation.com/tech_library/OBD-II_codes.shtml ) so yeah, maybe some kind of PCV trouble throws P0442?

Can smoke testing be done by home mechanics or is it pro only?

These trucks are getting old enough now that vacuum lines can be developing leaks from cracks. I had an 06 Mustang that would display that code maybe once a month, but it was so seldom that I never was able to chase it down.

Yep, intermittent codes are a pain. That's my current problem. Maybe I should just replace hoses one at a time until. Some of those hoses are expensive, though.

 

[Kira]

Can smoke testing be done by home mechanics or is it pro only?

Yes. You just need a smoke machine and a calm day.

 

[cbxer55]

Yeah, on mine, the hose from the fender to the intake under the throttle body had a YUGE blowout on the bottom. I just removed it, capped the fittings, and drove on. Been fine ever since. Tried hooking it back up one day with a new hose, ran like crap. Figured all the hoses under the bed are crapped out. SO I took it back off and put the caps back on. We don't have emissions inspections here. Light bulb for the CEL burned out years ago. LOL!!

EGR is gone as well, since the damn valve got stuck in the open position by a broken spring. Puppy runs swell and gets nearly 20 mpg. Not bad for a 3.0.

 

[calinva]

I'm in the middle of the same issue. Turned out a Squirrel had chewed the small vapor line that goes from the pump to the filler hose. Also the plastic gas line that runs from the pump to the fuel filter. Waiting for parts ? Pulled the bed off made life a little easier. Lucky it didn't catch fire. Had the code before smelling gas.