The check engine light can indeed go on if the gas cap isn’t tightened properly. But the code reader would say the gas cap or something associated with the gas tank vapor capture system was the cause. The code for this car didn’t say it was the gas cap. It says it is the cat converter. There are sensors before and after the cat, and if the cat is working, the sensors should read different values. If they read the same, that means the cat isn’t working. Unlikely to have anything to do the the gas tank. So, while there’s no harm trying, I doubt tightening the gas cap will work for @whitehonda.