97 Dodge Ram

All indication OF A BAD OXYGEN SENSOR
START BY CHECKING FUSES AND REPLACING O2 SENSOR
BEFORE THE CATALYTIC CONVECTOR ON BANK ONE

That would be the driver's side oxygen sensor ahead of the catalytic converter. You'll need a scanner to read the voltage the Engine Computer sees. The voltage is supposed to change from "rich" to "centered" to "lean" multiple times per second. That correlates to a swing of between around 0.2 to 0.8 volts. Normally if it stays in the rich condition too long, the code will state that. "Voltage high" could mean the 12 volt heater supply voltage to the sensor is shorted to the sensor wire. That is more often caused by wires in the harness, not the sensor itself.

To see if the sensor is the problem, you can switch them from side to side to see if the code changes to the right sensor. That's a lot of work when they are tight in the exhaust pipe. In the past, people have found melted wires when they started to do that.

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