One problem related to o2 sensor has been reported for the 2008 Jeep Patriot. The most recently reported issues are listed below.
The check engine light came on & I took it to a private mechanic. After testing it he said the error was from too much voltage going to the O2 sensor heater. He recomended taking it to a dealership for repairs. He also notice the safety cover over the rear break lines & fuel line had came loose and used wire ties to fasten it back in place.