Evap leak help

I've got evap leak code coming in. I had a frame swap a year or two ago. when I got my truck back I noticed the gas tank neck coming up, where you fill up, moves rather freely but i just got the engine code coming in so maybe it should be loose like that? I've also got an aftermarket gas cap ... help me out with the usual suspects i can chase down myself. before I have to break down and go get a smoke test.

Thanks people

Doug

 

To get the best help, let us know what the actual code numbers are for the MIL you're getting, current and pending. The info about the frame swap and the gas tank neck can definitely be important. The simple things to check with evap would be that the vac hoses are still secure and without cracks. It seems they all start to crack where they go onto the components

 

How old is the truck? do you live in a rust state?

Check the filler neck and hoses for holes (if you take the bed off it is super easy). My evap canister had a rusty solenoid and it needed replacing but you can't buy just the solenoid so I had to buy the whole canister. A vacuum leak in the engine bay could also be the cause, check all those hoses. Sadly this is one of the codes that can be rather tricky to diagnose.

 

Pretty simple to build your own diy smoke machine. Only think you might not have around the house is a regulator. I made one out of a cookie tin.

 

Code is P0442, 04 taco, 3.4l stick shift. Cleared the code a few times but it keeps coming in. Like I said I replace the gas cap with 14 dollar one from autozone. Made sure it clicks after I cleared code still came in 100 miles down the road. Looking under the hood now

 

I live in Illinois but bought truck in Utah and currently in PA. I travel all the time for work.

 

Some have had an issue with the fill neck and or the gasket at fill neck/tank. Also could be pin hole in vac lines anywhere from EVAP canister to all the way under the hood.

 

P0422 is an emissions code, not EVAP. https://www.obd-codes.com/p0422

Are you sure thats the right code?

 

Def EVAP leak code

 

Had the same issue with my truck. Some common trouble spots could be the filler neck and gas cap. I recommend replacing it with an OEM one if you can. Check the hoses going to and from your evap canister. Check the hoses going to and from your filler neck. Check the overfill check valve gasket to see if there are a bunch of cracks in it. For mine, I was too stubborn to get a smoke check done for a long time and I ended up spending way more than I should have to chase down the code. Also check you VSV valve to see if it is working.

I found this video to be helpful: https://www.youtube.com/watch?v=nxP4CuzV2EY