Hi evryone, new user here. I have a 2000 Accord 4 cyl, Coupe.
This Summer I wasnt using the car much, since I ride a bike. After three weeks of not using my car I took it for a ride, right away the idle started surging from 1000-1600, it once you put it in drive it was fine. It was acting like that for 2 days and finally it stopped. Check engine light came on, two codes. P0505 and P1457. 1457 was the vapor valve and I replaced that. I asked a friend to cancel the codes. After he did it the idle started go nuts. It goes below 400-300 and car starts to stall. it only works perfectly fine when in Drive and with AC on. Any help here on what to replace and how difficult it is to replace it?
Thank you

 

P1457 is not the "vapor valve". (What is that really?)

P1457 is a leak somewhere in the canister portion of the EVAP system, but you still have to figure out where. It can be caused by cracked/broken vacuum hoses around the EVAP canister, or any of a couple solenoid valves down there too. Also could be a bad EVAP purge valve (at the intake manifold)

 

I replaced the purge valve and the canister. I must've worded it wrong way. My main concern is that P0505 code and the wonky idle.

 

P0505 is idle-control malfunction. It's just saying it can't hold idle, just in case you didn't notice...

Try setting the base idle & doing the re-learn procedure.
https://www.hondaaccordforum.com/for...e-speed-38734/