Unable to put gas in car due to the gas cap missing

Need the right cap. May have to go to dealer or junkyard.

it would have been activated by an EVAP sensor probably a p0442 code
leak detected small or large ===possible cause cap loose or missing

Missing gas cap will most likely result in a check engine light. Upon reinstalling the cap after many drive cycles the light will extinguish.

In no case will a missing gas cap disable the engine.

Step 1 - Determine Your Type of Gas Cap Before acquiring a new one, think about whether you need a gas cap that locks to prevent a gas thief from stealing your gas. But keep in mind, if you put one of these caps on your car, your spouse or children who put gas in your car will need the gas cap key.
Step 2 - Remove the Cap Retention Ring When you actually replace your gas cap, you may need to remove a retention ring that keeps the cap attached to your car. If you do, you can remove it simply by using a pair of needle-nose pliers. Just slip one tip of those pliers under the ring edge; then close the pliers and pull the ring off the old cap and slip it over the new cap.
Step 3 - Check the Warning Sensor Light Your car may have a sensor light that will illuminate when you change your cap. If so, drive your car a few miles to see if the light goes off. If it doesn't, see your repair mechanic to fix the problem

next time take it to a accredited professional shop that will read the fault codes first before advising you on what has to be replaced and not just guessing the problem

The gas system is pressurized so you need a proper gas cap to allow pressure to build up and feed gas to your engine. Buy a replacement and put it on. The car should run fine.

The check gas cap light was in response to complaints of the check engine light being on for loose/missing gas caps. So now when the PCM sees a large EVAP leak the first thing it does is illuminate the check gas cap light (on models equipped with the light). Since it doesn't know if the gas cap is on or not it can have other issues like a vent solenoid stuck open which the PCM would be unable to distinguish between that and the gas cap left off.

There will still be a trouble code in the PCM for the EVAP system.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

The SES light will come on with a missing or defective gas cap. Try getting a new gas cap and installing to fix the problem.

Otherwise, have the SES light scanned to see what other problem may exist.

Hope this helps.

replace the gas cap

Yes in a cars fuel system ice can certainly cause problems. If the tank can not vent properly and ends up drawing a better vacuum than the fuel pump is capable of over coming due to fuel useage and the resulting vacuum created due to the drop in fuel level, then your car will just stop running due to fuel starvation. If there is a venting problem you would hear the air passing into your tank as your removed the cap. If anything it should be slightly pressurized vs having a vacuum in it.

Thanks for using FixYa!

Kelly