Originally Posted by Vindicator9000

BEFORE YOU START TEARING EVERYTHING APART AND REPLACING SOLENOIDS:

I chased this exact code on my 00EX for 2 years. I replaced just about everything evap related, and it was still throwing the code. I followed the troubleshooting flowcharts in the helms and all components checked out good - it was still throwing the code.

I eventually came to find out that my car throws the 1457 code 100% of the time if I overfill the gas tank, and that for some reason, the gas pump *NEVER* shuts off quite in time for my car - it may not spill gas out, but it fills it all the way up to the top of the neck. I suspect this happens to a lot of people, because I see a lot of questions on p1457 codes on 99 and 00 civics.

What has permanently fixed the problem for me:
When filling the tank, I'll run the gas pump full blast up to about 8-9 gallons, depending on how empty my tank is. Then, I'll run the last gallon on the pump's lowest setting. When I do this, the pump cuts off in time without overfilling. The key is to run the last gallon on low to prevent overfilling.

Once I started doing this on every fillup, I have never seen this code again, and it's been 2-3 years. I don't know why this fixes the problem, or why it's happening, I just know that this fixed it for me. Reset the code, run a few tanks like this, and see what happens. If that doesn't fix it, then change the gascap, and follow the troubleshooting flowchart in the helms.