The "test engine" light on my wife's 1999 Dodge Ram 1500 van came on
today. I put a OBDII tester on it and it showed a P0138 code meaning
"O2 Sensor Circuit High Volts (Bank 1, Sensor 2). I crawled under the
van and found two O2 sensors, one before and one after the catalytic
Does anyone know which sensor is the one indicated (bank 1, sensor 2)?