My check engine went on a few weeks ago, I took to get looked at (after checking gas cap was on tight)...was told was gas cap they replaced it...Few days later it came on again, brought it back, and NOW they are saying code ps0456, evap leak on top of gas tank, and I have to replace gas tank!! They want $1900 to do this...They are telling me the evap mechanism is in the gas tank??? This sounds kind of crazy to me...I did find a new gas tank at parts/junkyard place for $75, but they wont do it in case there is problem with that one....I'm lost on what to do!! any advice???
And if I try the other advice about fuel pump replacement, that was given to other people, is that a big job?
THANKS for ANY help!!!

 

Just an opinion, but I would do nothing, certainly not pay $1900 towards repairing it. Of course if your state/area has vehicle inspection or emissions testing that requires the check engine light to be off I realize you must do something eventually. Here is a link with a brief discussion of the cause of the code. You should see no drive-ability issues in the meantime.

 

You didn't say who "they" are, a dealer or an independent service garage. An independent garage may have used an aftermarket gas cap. They may not have performed a smoke test to locate the leak.

The gas cap is the most common source of an evap system leak. If the O-ring is not sealing perfectly, there can be a problem. Little deposits can build up on the sealing surfaces and cause gaps to exist. Make sure that the surface the cap seals against on the fill pipe is perfectly clean and smooth. Use an OEM gas cap.

If that doesn't do it, pay for a smoke test before you spend $1900 to replace the most expensive parts of the system.

 

I don't want to spend the money, but am moving to Texas soon where they have emissions testing.

I first found out about the problem from the dealership, who replaced the gas cap, then when light came back on then they apparently decided to look a little deeper. When I didn't believe I would have to spend that much, it being a dealership and all, I took car to local mechanic, who also ran fog test, and came to same conclusion...

I guess I just also find it hard to believe that the only way to fix an evap leak on a pacifica is a whole new gas tank?!? I had been doing some research online to see if true or not, and came across this site.