Hi everybody. I need to help diagnostic codes on a Subaru Outback 2005 wint 2.5 liter (NO U5 emission). DTC are P0031 and p0131 (O2 heater and o2 efficiency). With the snap-on MT2500 scanner, I can read the O2 voltage, it goes to 0.5 to about 6-7 volts. Is thi... Login to read more.