I replaced my gas cap and still the car says I need to (put my gas cap on). Has anyone had this issue? Is it a pressure sencor that is bad, or do I need to reset my computer?

did you replace with a OEM type or a generic unit

Professor, It could be one of many things. If the integrity of your EVAP Sysytem is breached then sometimes the DIC will have you check gas cap. You will need to really scan to see if any DTC'* are set. I'm assuming the SES light is not illuminated?

Your not speaking my language, but i'll try to answer. At first the check gas cap light came on, and then would go off, and so on for a couple of weeks. And then just stayed on The cap looked beat up (like you would expect it to work sometimes). After a while the check engine light came on. I then replaced the cap with a dealership cap and none of the warnings would go off. I was thinking that if you don't fix the problem for a while the engine light comes on. And at that point you would have to put it on a computer to get it to shut off. Either that or some kind of sensor is broken. What do ya think?

did you get the Code cleared?
after putting the new Gas cap on
try gettin the code cleared 1st

btw EVAP system is a PITA to deal with

I didn't "clear the code". How do you do that. $75 at the dealership? what a rip.

you can go to autozone or Advance and have them scan the car and clear the code

and its freee might i add

or you can unplug your battery for 10 minutes. (if you cant find an autozone)

The code will not go away by itself, in some case the PCM will do several test in optimal conditions before remove the code.

Professor, I'll try to speak your language, I am multi-lingual. DIC=Driver Information Center, this is where the "check gas cap" warning would indicate. SES=Service Engine Soon, probably a bad choice of words on my part, what I meant was check engine light. DTC=Diagnostic Trouble Code. At any rate, we'll need that code in order to begin to understand what is taking place with your car. If the EVAP system can't hold vacum then the Powertrain Control Module (PCM) will set a DTC. It will clear after so many start cycles, but the source of the problem has to be identified & corrected first. The problem may or may not be the gas cap. I'm thinking it'* not the gas cap in your case, but somewhere else in the system.