Cobalt SS Network - Fuel Problem???

Hey guys. My car (06 SS/SC) has been giving me some trouble since winter has set in and the temperatures are down. Today, for the third time since the beginning of November, my check engine comes on with the code for "Too lean" on bank 1. They always tell me it's bad fuel. I've now bought fuel from Sheetz, BP, and Exxon and got this warning light. When the light comes on, I run the tank empty, put some heet in, fill up, and the light goes off shortly after. It stays off till the next time I fill up and go through about an 1/8 tank of gas.

Is it really possible that I got 3 tanks of bad gas in a month and a half from 3 different gas stations? Or is there something else I should be looking at?

Note - the car runs no differently. It idles fine, has plenty of pickup, doesn't act strange under boost, no strange noises, nothing. If it wasn't for the engine light I would would think everything is 100%.

Oh yeah, and I always fill it up with 93 octane