Faulty Gas Caps/Small Fuel Emmission Leaks?

Hey all,

I bought a gently used (6000 miles) 4 door 2006 V-6 back in June of 2007. While I was test driving the vehicle, the check engine light came on... so the dealership ran a diagnostic, determined it was a fuel emmission leak coming from the gas cap, and replaced the cap.

The truck's been running like a dream until this week when the check engine light came back on, so I took it by Auto Zone for another diagnostic and it's supposedly the same problem.

Has anyone had the same problem? Could the problem be something else?

 

make sure you are putting the gas cap on all the way.... (or your attendant of you are in oregon.)

 

Any advise, 2011 tacoma, dealer replace gas cap and engine and traction lights off for 1 day, took it to a different mechanic for a smoke test after PO456 code and determine that test smoke shows smoke coming from gas cap. could it be something different. thanks

 

Did they cap off the vent line at the charcoal canister? You have to do that on Toyota LDP systems when doing a smoke test or you will always show a leak and it will be coming out of the filler neck area as that's where the vent comes out.