2005 Honda Accord check engine light came on. Manual says to make sure gas cap on securely. Took it off, put it back on and turned until it clicked. As manual suggested the light went away in a couple of days. My wife bought gas again and the light came back on a little while later. Could the gas cap be faulty and causing this trouble. I hate to go to dealer and spend a $100 for a diaognostic test only to have them say it is the cap
Why would you go to a dealer? First of all, you can take this to any good, local, independent mechanic. Second, large auto parts chain stores will usually read your error codes for free. Pull in, have them read, write down the exact code (e.g. P1234) and post it.
Gas caps are cheap - you could just buy a new one and see what happens. Clean the rim of your filler neck with some rubbing alcohol.
Changing the gas cap is a cheap thing to do to test it, but it would be even cheaper to take it to an auto parts store like Pep Boys or Advance Discount Auto Parts or Autozone and let them read your trouble codes for free. You can buy cheap replacement gas caps at the auto part store, but if you need a new one, this is a case where I would get an OEM gas cap from a Honda dealership.
If the light went away when you put the cap back on, then came one when the wife bought gas, have you tried putting the cap back on?
Maybe your wife just didn’t get it on tight enough. Both of my parents have a little hand strength problems.
That’s the most common reason for a newer car to do this. Turn the cap to 3 clicks to be sure.
Apply a little petroleum jelly to the seal of the gas cap. If the light goes out but comes back on at a much later time, replace the gas cap.
Tester
I agree with whats been said here, just to add dont buy a locking gas cap. They dont seal and youll really be going nuts over the light then.