Help! Exhaust warning light and gas cap warning!
 

So I get into Mozart yesterday and somewhere along the way I notice the warning light on. I look it up and it says something about the exhaust. Then when I get in the car to return home (I was only 5 minutes away luckily) it is now warning me to tighten the gas cap. I put gas in the car over a week ago, so haven't fiddled with the gas cap since then. I remember reading somewhere about someone having a persistent issue with this warning but can't find the thread anywhere. I'm going to try to take it by a MINI service place today (the place that installed the NM Engineering exhaust back in April) and see if they can check the codes. But thought I'd check here to see if there are any ideas or suggestions here.
Oh, Mozart is an '11 MCS and I just hit 3000 miles on the odometer. The exhaust and driving lights are my only mods.

Annette

Could be O2 sensor issue...?

What kind of exhaust? Could be the O2 sensor depending on where the pipe was replaced from. Just try to take a look from above or below and see if something was left unplugged. GL