One problem related to manifold/header/muffler/tail pipe has been reported for the 2011 Jeep Patriot. The most recently reported issues are listed below.
After hearing a noise in my exhaust system, I checked under the car and found my muffler locked up about 2 to 3 inches with the exhaust pipe pointing directly at the back of my plastic bumper. My bumper was distorted and melting. I caught this problem before a fire started but am confident this would have ignited. I then reached up and pulled with a little force down on the muffler and it snapped back into the correct position. There is no damage to the underside of the vehicle just the damage to the melted bumper. I went to a dealership and showed the service manager the problem. He took pictures and contacted Chrysler. After waiting almost two weeks, the service manager contacted me and told me Chrysler would repair my bumper as a courtesy. I asked him if they were going to fix the problem with the muffler/hanger but they refused. I am now doing what I can to inform people of the problem and trying to get the problem fixed. I also found a video at oregonlive. Com which details the same problem with my vehicle.