I've been getting this engine light and finally got the code read and it was P1457 which is related to the Evap system. I've tried locating the canister and couldn't find it on the engine bay. I looked under the car and I think that its the black square box located in the center under the car.

Has anyone tried to troubleshoot this problem?

Jeff

"Topping-off" your fuel tank after the fuel pump automatic shut-off will cause a P1457 code (EVAP leak or problem in the circuit at the canister end of the van). My advice is to not do this if you are. Second, make sure the fuel cap is turned at least a good 3 clicks after fuelling. Failure to do this can cause a P1456 code (leak in the EVAP system or problem in the circuit at the fuel tank end of the van).

I would suggest you reset the code and see if it comes back to rule out an intermittent problem.

If the P1457 code comes back on:

DTC P1457 EVAP Control System Leakage

1. EVAP Purge Control Solenoid Valve Test
2. EVAP Bypass Solenoid Valve Test
3. EVAP Control Canister Vent Shut Valve Test
4. Cannister System Leak Test
5. Evapolative Emission(EVAP) Two-Way Valve Test

I've reset the ECU many times and it keeps coming back after a few days
with the same code. I always tightened the fuel cap more than 3 clicks
after I refilled fuel.

How hard is it to change/fix? Does anybody have a diagram of the evap
system?

P1457 = Unable to pull a vacuum in tank. NDNV definately covered it all. Something is leaking to atmosphere or your purge solenoid and/or associated vac lines are leaking. Pulling a vac on the gas tank must happen during a system cycle or test. Normal condition would be slight positive pressure on the tank. Gas caps have an internal check valve that sometimes don't seat, or they stick or leak.

Joel