Gas cylinoid/Check engine light

Oh it was loose, now I am just worried if I didn't put it on tight last friday...

Most probably, you were distracted and forgot to tighten it. (Cute gal at the next pump?)

;-]

Yes, AutoZone is probably correct, this could just be that the gas cap wasn’t on tight. If not that, it is probably an evap purge valve on the fritz. As mentioned above, federal regulations require that new cars don’t allow gasoline vapors to vent to outside air, which causes air pollution. But a method must be incorporated to allow air into the tank as the gas gets used up while driving. So it can be somewhat complicated. If you’d like to know a little more about how a car’s evaporative control system works, here’s a pretty good link.

http://www.agcoauto.com/content/news/p2_articleid/294

Well CEL went off today so I guess it was my lack of a tight fuel cap that was the issue.

So…you got an EVAP Emission code… and ? This code means that the gas tank is venting to the atmosphere…OR that it HAD at one point in time… Many times this is caused by filling the car while it is running… A leaking gas cap…OR and this is more common… A rotted rubber hose that is within the closed loop system of the gas tank and its venting system. Very common and easy to repair IF you can find the offending rubber hose.

Reset the codes (Disconnect the battery for a minute or two) and drive a while…see if this returns… My guess is that it will not…if it does then it is time to start searching for where the gas tank is venting to the atmosphere…again…gas cap…rubber hose… or any other valve in the Evap Emissions equipment. ALL MINOR STUFF

Blackbird

The drive cycle for some models can be very complex. First, prerequisite tests must run and be passed. Then, at a stated temperature and engine temperature level, with a certain minimum amount of gas in the tank, it will run the tests.

Of course, this may vary from make to make. I have been able to find the drive cycle description for some tests on my car, on-line.

In an ideal world the manufacturers would publish for anyone who wants to know what the rules are in the ECM computer program for the check engine codes and the lighting the CEL. Alas, not an ideal world.

GM and Ford make such information available for free

https://service.gm.com/gmspo/mode6/

http://www.motorcraftservice.com/vdirs/retail/default.asp?pageid=diag_theory_retail&gutsid=diagsheet

We’re only concerned about spelling here and cylinoid is correctly spelled. What it is though, I don’t know, but its spelled correctly. Just being a smart aleck.

@Bing Shouldn’t that be “smart aleck”? Sorry, couldn’t resist.

Well that’s what I had but spell check changed it.

Meh - what does spell check know?

C can be used for “S”. It’s arbitrary. There’s a Cecret Lake lake at a ski resort in Utah. There’s no confusion there about how it is pronounced or what it means.

Good to know that GM and Ford are onboard the plan to make the technical information car owners need to repair their own car or to communicate with their own mechanic available for free to everybody @db4690 . B/c of this I’ll be more likely to consider a Ford or GM product should I purchase a car. Thanks for the info.

@GeorgeSanJose

here’s more stuff for you . . . VIN information and sockets/pigtails are particularly useful

http://acdelcotechconnect.com/

here’s another good one . . . click on archive, then vehicle information kits

https://gmheritagecenter.com/