i drive a 2000 honda civic si. currently it has the CEL p1457 which is EVAP system leak detected in the canister system. this CEL has been ******* me for a while now and i am fed up with it. so far i have replaced the vent shut valve solenoid and the 2way bypass valve...with no luck. i am trying to fix this problem without spending a fortune and so i would like to here what some of your opinions are. let me know if you have had this problem and how you fixed it. the car drives great otherwise.

 

ah the famous p1457 code...what a PAIN it is...grab urself a helms and follow the steps in diag so you dont end up spendin money on parts you dont need to fix it

 

I fought that code on my 2000 EX for 3 years and replaced just about everything (hoses, purge valve, gas cap, etc). Following the helms flowchart indicated nothing was wrong. Finally figured it out (at least on my car).

Mine throws that code 100% of the time when I run the gas pump on full blast at the end of a fillup. It's like, it doesn't click off fast enough and slightly overfills the tank.

If I run the last 3-4 gallons on the lowest setting of the pump and let it click off slowly, then DO NOT top off, I never get the code. Ever.

Try that. I'd be interested to see if that causes it in just my car, or for other people too.

Interesting... I now have a OBD2b P72 and a gsr motor, and I still get the P1457 code if I overfill it.

 

my problem was the ecu...somehow the evap circuit got fried in the ecu..replaced that with another one and the code was gone

 

Start simple by checking whether the seal on the gas fill cap is bad and leaking. If the cap is fine, then check for possible leaks in any of the EVAP system vacuum hoses and connections.