Gas cap light, then engine light.
We have an aftermarket gas cap on my wife's 2006 ZX3. She insisted on cutting the retaining lanyard on the original cap, and of course, lost it. We have since had to replace two more caps.
The latest is your standard auto part store replacement, not factory. Had it on about 1 year or more. A couple of times we've gotten the warning light about the gas cap, but it has gone away after a few hours.
Now the light has been on for 3 days, although the cap is securely in place. I've removed it several times, cleaned around the cap, etc, it won't go off.
Last night, the engine light also came on.
The car is well maintained, and I feel the engine light must be related to the gas cap issue as well. Its about 30 miles to the nearest Ford dealer, and diagnostic computer.
Planning to try that tomorrow, but just curious if the consensus is the two are related.