sensors are not protected by fuses.
O2Sensor.
All O2 sensors are threaded into the exhaust system at various points.
That would be located under the car just in front of the second catalytic converter.
upstream will be in the manifold, downstream refers to behind the converter Upstream o2sensor on exhaust manifold . from underneath have to reach up to where meets up with block. hard to reach . but not impossible
Check and see if someone installed an engine core heater. This could have happened if the car was ever in an area where the winters get very cold.
use higher heat rated spark plugs, it worked for me.
fixed problem after afew times double checking everything .. it was a blocked catalytic converter
The O2 sensor heater circuit helps warm up the O2 sensor. The purpose of this is to allow O2 sensor to get to normal operating temperature without having to wait for exhaust pipes to warm up so it can give accurate readings. It is built into O2 sensor.
the o2sensor(oxygen sensor)is on the exhaust if i recall right. There are (2) oxygen sensors on the 2001 Dodge caravan (in this case Sport / SE edition) One is accesable under the hood the other is down in the exaust array past the catalytic converter. If your error message is showing that your heating element is out in the O2 sensor... its the front sensor.
It takes one O2 sensor available at any parts store. There is a special tool that has a slot so you can remove the sensor and replace with the new. There is a factory connector. 5 minute job. Sensor sits on top of pipe just ahead of catalytic converter.
Fuel immobilzer fault. ( running to rich) check connectors from key to ecm. Check vacuum lines around intake and air box. New has cap (Volvo). O2sensor may need to be replaced. On stone cold engine drive a straight away 2-5miles, at 55-60mph. Also check battery connection, and ground wire to car may throw sensor reading off