Gas cap message

[ram5.7hemi]

Ok so a while back I had a gas cap light come on in the instrument cluster, I replaced the gas cap its self just in case it was broken or wasn't sealing, reset the codes using bullydog and 3 days later it came on again, I took it to a mechanic and he did a smoke test and tested the charcoal evapotive canister,smoke test was good but a valve on the canister was bad so we replaced the canister itself, 3 days later it came on again, we thought possible the bully dog was stoping it from resetting all the way so we cleard it out unplugged it and then he used his little computer thing you hook up to that port to reset it.... 3 days later billy dog completely unplugged it came back on,

Has anyone ran into this problem? What the heck is stopping it from resetting or making it come on still?.

 

[jwheeler]

What is the code? When did he replace the canister?

 

[cyclepuck]

Has same issue on my truck first week I got it. Ended up being the fuel tank pressure sensor.

 

[ram5.7hemi]

What is the code? When did he replace the canister?

not sure but it says "small evaporative leak(gas cap)" canister was replaced about two weeks ago

 

[ram5.7hemi]

Has same issue on my truck first week I got it. Ended up being the fuel tank pressure sensor.

Where is that sensor located at? How do u check it to see if it's bad?

 

[cyclepuck]

Not sure. It was covered under warranty but I believe the sensor is on top of the tank and no clue how to check it.

 

[jwheeler]

There is no fuel tank pressure sensor on a 3rd gen. If his has one, it must have started this year.

 

[ram5.7hemi]

There is no fuel tank pressure sensor on a 3rd gen. If his has one, it must have started this year.

It's a 2008 quad cab 1500 4x4 hemi laramie