Need some help!!
 

Hello Mustang Enthusiats....I recently bought a 2000 Ford Mustang V6 3.8L...however, it is giving me a small problem. My Check engine light keeps popping on every so often. I took it to AutoZone and they pulled the code "455" from my check engine light, which reads "EVAP LEAK LARGE". The steps to fixing this by the book were, replacing the gas cap, then the EVAP canister, then something about the vaccum of the engine was messed up. I am totally lost about what I should do to fix this problem. When I see the light comes on, I dont notice ANY lack of performance whatsoever. Someone please help!!!

check your gas cap, if it wont seal correctly it will do that. more than likly thats what it is.

yeah new cars get CEL from the gas cap not being on tight enough , take a look at that first.

Thats would it should say on the inside of your fuel door. Thats most likely whats wrong. Let us know what happens.

Right, that's the first thing I did...was change my gas cap...and replaced it with the locking cap...and still the light comes on!!

There is a test service port on one of the main EVAP lines, it has a green cap on it. Either slighty pressurize the EVAP system from that point with a vacume pump. Or start checking all your EVAP lines, Vacume line for leaks with the vacume pump as well. Pressurize your EGR valve.Check the vent line that comes from your gas tank. Make sure it isn't cracked or broken anywhere. Make sure the port that goes into you EGR from the intake is all clean. If all that checks out good then I would replace DPFE sensor. Hope this helps you out...

if its an aftermarket one it might not be sealing well.