Hi BillRussell, until someone steals your gas cap, oh wait- that was me lol 
Yes, if the CEL is being caused by an evap system diagnostic code, replacing the cap with an OEM unit will probably turn the CEL light off. Eventually, it may take a few drive cycles first.
So if I have this correctly, your gas cap door does not latch closed, but you can close it. If so, you could get some stick on magnets that would hold the cap in the closed position but you could easily open it. Most people do not go around checking to see if the gas cap door (fuel door) can be opened. That should keep anyone form stealing your gas cap.
Now a new OEM cap should solve the CEL issue and you should be good to go for very little money.
Why not just stop into your local Honda dealer and find out what it may cost you to repair the door. It is probably just the cable that runs from inside thew car to the fuel door.
I doubt that the cable would be available to parts stores, but you can ask.
Yosemite
Thanks you guys!
Yosemite: If the OEM cap can solve the CEL, I might not have to, well, at least not at first.
Get Another Free Code Read. Verify That Youāve Only Got A Code For An EVAP Leak, Like A Large EVAP Leak, Setting A Code Like PO455, Likely A Poorly Sealing Gas Cap. Make Sure Another Problem, Unrelated To The Gas Cap Hasnāt Popped Up. A CEL Can Alert You To One Fault Code Or Multiple Ones.
Take advantage of the free reads and keep in mind, for birthdays or holidays, that you could be gifted your very own code reader, like an Actron Pocket Scan (can be found for around 50 bucks, sometimes even at Advance Auto Parts sales).
You could plug that little beauty in yourself, read codes, and shut off your CEL if you choose!
Feel the magic! It will set you free!
CSA
Iād bet money that you actually just forgot to put the gas cap back on when you filled up.
If you can remember where you bought gas before it was missingā¦just stop in and ask.
Iāll bet they show you a box full of caps that were left behind. Take the box full out and find one that fits.
Yosemite
Iāve used non-OEM gas caps before and had drivability problems which were solved by going back to factory standard ones.
Thanks guys! The CEL light only started coming on after my gas cap was stolen- common sense answer- but thanks for all the advice!!!
Well, I did get an OEM from the dealership-also found out when I brought my car in for an oil change yesterday- that was not the only reason my CEL was lit. One of my 02 sensors is acting up. The clerk at NAPA said he could sell me the part and if I looked into it, I could find (i.e.internet) detailed instructions on how to change one.
However, if I have three 02 sensors, like Firestone said, I donāt think it is wise to change one without knowing which one to change!! lol-aaahhhhh!!! I should have been a mechanic. Eventually, Iām going have to find a way to move to the cities. I hate neglecting my vehicle but, eventually, I probably wonāt be able to afford to drive in this capatilistic society
I probably won't be able to afford to drive in this capatilistic society
Well, Cuba is much easier to get to these days, and they have a lot of neat old cars to look at, too.
;-]
I know-insightful-every society has its problems. Iām just venting
June 13
" Get Another Free Code Read. Verify That Youāve Only Got A Code For An EVAP Leak, Like A Large EVAP Leak, Setting A Code Like PO455, Likely A Poorly Sealing Gas Cap. Make Sure Another Problem, Unrelated To The Gas Cap Hasnāt Popped Up. A CEL Can Alert You To One Fault Code Or Multiple Ones. "
June 15
" The CEL light only started coming on after my gas cap was stolen- common sense answer- but thanks for all the advice!!! "
June 18
That is why I advised checking for codes, again. Itās also, why I advise not to drive around too long with the CEL lit. Thatās also why I advise owning a code reader.
My local parts guys would turn off your CEL if you requested. I guess in some locales they wonāt, another reason to have your own reader.
If this was my vehicle, Iād turn off the CEL and see how long it took to get another O2 sensor code. It might never come back. I canāt tell you how many times Iāve cleared a code and never had it reappear.
Are you sure itās a code indicating a problem with a sensor/sensor circuit, specifically, and not something else causing the sensor to give an out of range reading?
Find the exact code and post it here. Weāll take a shot at it.
Also, capitalism is working great for many of us. When in Rome, do as the Romans. When living in a capitalistic country, do as the capitalists, do!
Iām full of it, today. Free advice, that is.
CSA
Rusty does not trust mechanics but listens to a parts counter person and goes to Firestone. OK Fine.
When I said I did not trust mechanics, I said that as a generalization because of negative experiences getting hosed. I am willing to put my trust into Firestone because they have worked on my vehicle before and have seemed to be on the up and up, but, yes, I will never know for sure whether I am being lied too and the truth embellished because Iām a stupid girl who works in the medical field and not the automobile industry!!!
I try to stay as knowledgeable as I can. I am sorry if I insulted anyone with my comment about living in a capitilistic society. That was all I said. I did not type out a paragraph concerning my political views because this is not the forum for that.
To CSA- I have the paperwork from Firestone at home. I will dig into it to try to find the exact code. Iām sorry. I did not know an 02 sensor indication wasnāt that big a deal. I donāt know anything about cars and am sorry for sounding so idiotic.
Also- CSA- I asked both the auto parts store and Firestone to turn off the CEL and both told me if their code readers are picking up something related to an 02 sensor (both places said they were) than even if they were to turn off the CEL (again, both places said they did) it would automatically light up again until the 02 sensor is replaced or a diagnostic run to assess and determine the issue.
It sounds from reading your reply, however, that this shouldnāt be a big deal and their should be no issues with turning off the CEL. I do not know if I am understanding correctly, so please inform me if Iām misguided. Again, thanks everyone.
The O2 sensors are used to make small adjustments to the air/fuel mixture for improved mpg and reduced emissions. And to monitor how well the catalytic converter system is working.
Without knowing which O2 sensor is the problem, hard to say what to do.
It is quite possible thereās nothing wrong with the O2 sensor, and that the reading from that sensor is messed up due to other non-sensor related reasons. For example if an injector stuck open and spewed gas into the engine irrespective of how much air was going in, that would cause a rich condition that the computer couldnāt do anything about, the O2 sensor would continually read ārichā, rather than bouncing back between ārichā and āleanā like it is supposed to, and the computer might consider that symptom a problem with the O2 sensor.
Since you are in the medical field, you use sensors to measure the oxygenation of the patientās blood, right? If the sensor reading says the patientās blood has a lower O2 concentration than normal, is the problem usually the sensor?
As mentioned above, post the actual codes here. Youāll get some ideas what to do next. Usually the next thing isnāt to replace the O2 sensor.
Capitalistic society . . .
Because a car owner is expected to pay for their own repairs . . . ?!
As promised- here are the codes picked up by Firestone as well as what is written next to them:
P1456=EVAP control system leak
P0135- 02 Heater Circuit
Thanks again guys!!!
Have A Buddy Or Auto Parts Store Help You Check Fuse #15 Under The Hood. That Could Tell You If There Is A Shorted O2 Sensor Wire. It Seems Fairly Common For These Vehicles To Develop Wire Damage And A Short Circuit Where The Sensor Wire In The Engine Wiring Harness Is In Contact With The Intake Manifold Bracket. It Is Possibly Not The Sensor Itself That Is Bad, But Rather A Wire.
This Honda is a geriatric patient and things do become worn and cause some aches and pains and other ailments.
CSA