Evap leak fixes?

I recently brought my 01 Mitsubishi galant es into autozone for a diagnostic. The error was a evap large leak. What will cause this error. Check engine light comes and goes while driving. I checked my gas cap it is loose so im gonna attempt to get another one. I have tried playing with it but light will not go off.what else should I look into.

Error code was P0455

Assuming the loose gas cap was the cause of P0455, the light will eventually turn off on its own

Perhaps in a few days

A loose gas cap can cause that code.

I’ve had vehicles come in with that code. And when I went to check the gas cap, it wasn’t there.


If a new gas cap doesn’t fix it, have the system smoke tested to pinpoint the leak.

It takes at least three drive cycles for the light to go off.