Idle Stumble Question

2002 GTP 82k miles. It has a few mods listed below. Earlier in the year I had issues with the idle being very loopy to the point it would stall out. It only did it when it was raining, my dumbass cut a hole in the fender. I chalked it up to the filter getting wet. So I patched the fender hole.

Fast forward 3 months and hurricane Sandy rolls though. Go out to my car this morning start it up and ta-daa the problem is back. Driving today it threw a code for a bad o2. I cleared it and it hasn't come back. Idle is still loopy and stalling out. It'll do it for maybe 5 mins rev the engine up and it'll clear up and drive fine. Turn the engine off wait 5 mins and start it back up and your back to square one.

The o2 code today was the first check engine light in a while(10 months) or so.

What else could this be? No vacume leaks according to my gauge. Map sensor maybe?

Plugs, clean TB maybe some lucas fuel cleaner. Didnt you guys get snow down there? Might want to look into some heet or whatever it is to get moisture out of your tank. I usually run a bottle or two once before winter weather and one during. GL

All that is good. This is an all of a sudden type thing. I filled up with a fresh tank today. Before the culprit was bad gas, I was bike commuting to work for 3 months or so. It straightend right out last time. This time not so much.