Engine light stays on,replaced fuel cap per auto parts store.still light stays on,also fog lights dont work but car runs good

You cannot make the check engine light go off by replacing or removing a fuse. You need to fix the problem that is causing the light to come on. It might be as simple as replacing the gas cap. I would take the car to AutoZone or another auto parts store and have the trouble codes read. The store will usually give you a printout of possible problems associated with the code(s). If you want to spend the money you could buy a code reader and read the codes and then clear the codes which will cause the check engine light to go off for a short time (maybe long enough to get theemission test done if you're lucky!).

Well, don't guess at it like that, get a readout of the trouble code stored in the car's ECU. Any auto mech can do this for you, and in the USA Autozone as well.

You will find a code like P0135 or some such, and this will have a meaning specific to your car, so you can home in on the fault.

No parts are ever replaced to resolve any vehicle issues

You have to proper test any vehicle systems that apear
to have a problem

Once all the answers are present, only then do parts get
installed if necessary

Things such as fuses & relays only fail here on these web site
blogs, for the most parts,way too much silly talk about nothing

Need to have the car at a repair shop that actually can diagnose
something

From what I see on this site from people asking questions,
that appears to be an issue also,finding a half decent shop
these days

You wouldn't think a gas cap would be that important, but it is. When it's loose or cracked, fuel vapors leak out and can throw the whole fuel system off. This causes a reduction in gas mileage and increases emissions.
What causes it: If you get an error pointing to the gas cap it means fuel vapors are leaking out of your cap. This means the cap is either cracked or just wasn't tightened well enough.
What you should do: If your car isn't feeling jerky or strange when the check engine light comes on the first you should check is the gas cap. Pull over, retighten it, and take a look at the cap to see if it has any cracks in it. Continue driving and see if the check engine light turns off. Alternately, you can purchase a gas cap for about $3 at an auto parts store. All you need to do is take the old one off and screw on the new one. If you've already made it to the store, you might as well just replace it. While not car-threatening, it's good to take care of this right away to improve gas mileage.

you could have a bad engine coolant sensor. or if the check engine light is on get it scanned for the problem code. most auto parts stores will scan for free, if check engine light stays on.

Diagnosis must begin with scanning your Engine Control Module to find out why it has turned the light on. The car may seem to be running OK, but there is probably a problem that is causing you to use excessive fuel and/or is threatening to destroy some high dollar parts like your catalytic converter.

The check engine light can be anything, in order to help you further you need to get the codes out of the computer. to do this you need to either A. Buy a cheap code reader from an auto parts store, B. Go to an auto parts store like Advance, or Autozone or pep boys, and they Usually will read the codes for you for free. Then you need to post back here with the code read, and We can help further

The quickest way to determine the cause is to visit a local parts store, of a major chain such as Autozone, etc. most of these offer a free computer scan that will reveal the source of the engine light. In the mean time, try refueling with a full tank of fresh fuel from a different source than you used the last time. sometimes water or other fuel problems can cause the light to come on.

And yes the loose fuel cap may cause the light. If you have more than 60,000 miles on your car, it may require some tune up parts such as oxygen sensors and such. CHECK YOUR WARRANTY!!! most states require the manufacturer to replace the emission related parts at mileages of 100,000 or even 150,000 so dont buy something you could get for free!

Good Day,

Probably just a bad seal in the cap. You can purchase a new one from any auto parts store or dealer. Just make sure they cross-refrence the new cap to your car as diffrent caps have diffrent pressure ratings, and you wanna make sure you get the right one. And yes a faulty cap can cause your check engine light to come on as the fuel is not pressurized properly for the motor. Once the cap is replaced with a new one remove your negative battery terminal for a few moments, then re-connect this will clear you check engine light. If you don't do this you engine light will stay on forever.

Good Luck
Hope this helps