Can you give me the model and engine size of this Jeep, and the p-code that you have?
Ok. Do you have the actual p-code related to the issue you stated above?
Ok. This p-code is pointing to a problem with the internal heater for this oxygen sensor. The PCM uses this internal heater to get the sensor to normal operating temps within a matter of seconds on cold starts. Replacing the oxygen sensor for bank 1 sensor 2 should solve your problem. This sensor is mounted to the exhaust pipe, on the driver's side, behind the catalytic converter.