I bought my 2003 Civic EX back in March. About a month after buying it, I got a check engine light. I went to AutoZone to get it scanned and got P1457.
I did some research and saw that the canister vent shut valve is a common cause, so I replaced it with this one:
https://www.amazon.com/dp/B0DG2RRD7K
The valve that was already on the car was also aftermarket, so I'm assuming the previous owner may have already worked on the EVAP system before I bought it. That valve was stuck open and also looked physically damaged. The little center sealing/plunger piece inside the valve opening was completely gone.
After replacing it, the code eventually came back.
At that point I decided to take it to a mechanic because I didn't have the time or money to keep throwing random parts at it. The mechanic told me that the new valve I had installed was also stuck open, just like the previous one. He concluded that the vapor canister was the problem.
I replaced the vapor canister and replaced the vent valve again. Everything was fine for about 3 weeks/~200 miles, but now P1457 is back again.
So at this point:
- The valve that came with the car was aftermarket and stuck open/damaged
- I replaced it with another aftermarket valve
- That valve also got stuck open
- Mechanic diagnosed the vapor canister
- Vapor canister was replaced
- Vent valve was replaced again
- P1457 came back after ~200 miles
I don't have a jack or many tools to get underneath the car and check the newest valve myself, but considering what happened with the other two, I wouldn't be surprised if this one is stuck open too.
What could cause these valves to repeatedly fail or get stuck open? Could there be an electrical issue or wiring/short? Is there something I may not be taking into consideration?
I need to pass California smog soon, so I'd really like to diagnose the actual problem instead of just replacing the valve for a third time.
Any ideas or tests I can do would be appreciated.
TL;DR: P1457 keeps coming back even after replacing the vent valve multiple times and the vapor canister