Oil light on at idle

Just had my oil changed about a month ago. Everything was fine until a few weeks later after getting a resonator replaced. Oil light would intermittently stay on longer than normal when starting up, but would quickly turn off again and stay off. A few nights ago, the light began to flicker and stay on when slowing to a stop or idling after driving for some time, but shuts off again when I apply any amount of gas. Is this more likely to be something minor or serious? If I take it in for repair, what should I have them look for? Any help is appreciated

It always amazes me to read that anyone continues to drive even 10 feet with an oil light on. Yes, it's PROBABLY a bad oil sensor, but there's also the possibility of true low oil pressure, which likely means the engine is well on the way to being trashed. A shop will be able to quickly diagnose and repair (if the problem is a bad oil sensor).

I second avguy's response. I had a good friend who was ignoring his pesky oil light that eventually went off and stayed off as long as he was driving. I replaced his engine for him about three weeks after that started happening.

It's quite possible that the drain plug or the oil filter weren't screwed on tightly enough, and that you're leaking oil, and it's coincidentally just now that your level is getting low. Or, your pump could be on its way out. Or the sensor and wires could have been whacked when they were working on your resonator. I would definitely get it checked ASAP. I assume you checked your dipstick? What does it say?