PO136 is Bank 1 Sensor 2 low voltage detected.
PO141 is Bank 1 Sensor 2 heater circuit malfunction.
You're in need of replacing the Bank 1 Sensor 2. It failed both the warm up heater and the sensor itself.
Bank 1 is the side with the #1 cylinder and Sensor 2 is after the converter. This O2 sensor only monitors the converter and does not effect fuel mixture. I would have a Mitsubishi mechanic at the dealer read the voltages of all the O2 sensors, I seem to have a faint memory of the codes coming up for the wrong sensor location on some of the model years.