One problem related to o2 sensor has been reported for the 2004 Dodge Ram 1500. The most recently reported issues are listed below.
Check engine lite keeps coming on. Have taken to dealer 4 different times. Dealer says issue is with O2 sensors. Second time in all sensors and computer replaced. Still is occurring. Dealer said they where bringing in field service tech on 3rd time. Last issue occurred 30 March 05. Dealer is unable to diagnois case of issue.