P1131 is pointing at lack of operation of the Heated Oxygen Sensor Bank1 Sensor1. More than likely the heater circuit in the sensor has gone bad. This heater is used to get the sensor to "normal" operating condition in just a matter of seconds. The reason it comes up as "Manufactur's Controlled System" is because every manufactuerer can instill their own personal codes into the OBD system to more easily and quickly remedy thier most common problems. Replacing the oxygen sensor Bank1 Sensor1 should solve your problem. It is located in the top of the exhaust pipe (before the cat) closest to the firewall.