How do I tell which o2 sensor is bad?

[Wilz02wrx]

Does the 0031 code tell you which sensor is bad? i ask because i unpluged the front o2 on accident (someone had given me the location of the o2 sensor plugin come to findout ti was the front they told me) no new code came up or anything so now i think it could be the precat one i really dont want to spend the money to buy both is there a way to figure out which one is causing my problem?

[Rogan]

0031 = Front O2 Sensor Low Input
0032 = Front O2 Sensor High Input

0037 = Rear O2 Sensor Low Input
0038 = Rear O2 Sensor High Input



Of course, the front O2 is the salty dog..

[Wilz02wrx]

ok yeah i figured that out now i unplugged both and when i unplugged the back one a new code came up. so low output means i need a new one right?