After my check engine light came on and then reading the owner's manual section on this topic for advice, I discovered that the gas cap was not installed tightly. The manual and text on the original cap both warned that this could cause the check engine light to come on. The manual further advised that tightening the cap would not immediately cause the light to go off, but htat a few trips may be required before that would happen. I have driven the vehicle for several days (approximately 20-25 start/stop cycles, and one trip of approximately 60 miles) since tightening the cap but the light is still on. Assuming the loose gas cap was in-fact the cause of it coming on, any idea if it should be off by now, , or how long it may take to correct itself?

I'm not sure how many cycles it takes to reset the light but I'm pretty sure it should have done it by now. I would have the codes read again to see if something else is causing a problem.

Visit you local auto parts store, most of them will read the code for free and many will clear simple codes like the gas cap. Later

Thanks for the tips. As it turns out, the light went out several days after I posted my question, and before I made it to get the codes pulled. Apparently it finally reached whatever thresholds are required to reset the check engine light to off.