Can somebody please help us here, we have a 2008 F150 with a 4.6 V8, I changed the gas cap and cleared the code, but it has come back three ties so I know something is up, and its not the cap. Thats why I made this thread, I've been working on cars and trucks since I as 10, but they were all Chevy's ( figures huh)
Anyway I have this little $20 code reader and when I plug it in and press read it says P0442, Somebody told me it was the canister purge valve line, but being that the newest thing I have worked on was a 1976 C10, I'm kinda lost here

 

It's a leak in the evaporative emissions system. Unless you want to guess at what the problem might be, take it to a shop that has a smoke machine.

 

Thanks, I'd rather find it myself since money is a major issue and I am pretty mechanically inclined, unless I do end up taking it somewhere should I start in the rear above the spare tire or somewhere else?

 

Make sure you used a good quality gas cap, not a cheap aftermarket replacement.
Do a visual inspection of the system.
Check for any cracking or damage to the evap canister.
Check the vent valve for contamination (dirt, insects stuff, etc).

 

Ok on mine is the evap canister the thing above the spare tire? And just in case where is the purge valve located at, I looked on-line and found about 50 different places and 50 different styles of valve

 

I got another cap, this time I bought it from the dealer, they sold me a Stant, Hopefully this solves it, cause I did a visual over Thanksgiving weekend and nothing is broken cracked, or out of place anywhere in the whole truck

 

On my 2002 4.6 FX4, during a thermostat change, a visual inspection revealed a 'dry rotted" hose in the evap system.
An inspection of the entire system turned up no other issues. The hose from the VMV to the throttle body was rotten. I touched it and rubber flaked off and left black on my fingers. I replaced the hose and the truck seemed to idle a bit smoother. I guess it was sucking air even though no holes were found. Lesson to me: check the hoses periodically to avoid breakdowns. That could have been a big issue on the side of the highway in winter.

 

I looked everywhere under the back end over the weekend visually and saw nothing, this coming weekend I'll be removing and physically inspecting the rear components. If I find nothing I'll start under the hood and body physically inspecting bin stead of just looking,
Oh and just and update the light only comes on at 1/4 tank or lower if ghats a clue, don't know if I already post that or not I'm on my phone posting right now cause windows crashed again