Check gas cap light is on after replacing stock with aftermarket cap

SOURCE: check engine light came on along with check gas cap

Did u have engine codes scanned? If not, have it done, as it may indicate the problem. Let me know. (most parts stores will scan for codes free) .

SOURCE: moisture in truck, with check gas cap message on dash

The two are of course not related. Check the trunk seal for missing portion, tears, splits, etc. this has to be where the rain is coming in. You can check for leaks with a hose and climb in the trunk with a flashlight, having a trusty helper direct water to one area at a time to check for the leak. The gas cap light is probably on due to a defective evap. vent valve, which is located behind the left rear tire near fill tube for gas tank.

SOURCE: I have a 2006 grand prix and the check gas cap is on. Why?

Check the interior seal inside the gas cap--could be damaged or collapsed. Replace cap if damaged. Try clearing fault code by disconnecting one battery terminal for little while, then reconnect. This clears the fault memory in the computer. The other way is to have the code read and cleared with a reader.

SOURCE: on a G6, check engine light is on as a result of

Hi:
The gas cap fault is very common on this line of GM cars, and if you check your gas cap and have tightened till it is clicking, If you clear the code and it comes back, you need a new gas cap.

Most auto parts stores will read and clear your codes for free, so ask around.

SOURCE: own a 2008 pontiac torrent gxp

The system is set up by GM to have the cleared with a codes cleared by a OBIII hand held device which can be purchased at many auto parts stores. Auto Zone can clear it for you for free if you ask them to do so. If the code does come back you may want to purchase a factory fuel cap instead