One problem related to o2 sensor has been reported for the 2001 Volvo S80. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2001 Volvo S80 based on all problems reported for the 2001 S80.
Sputtering and stalling of 2001 Volvo S80 t-6 at low speeds. In June, Volvo authorized dealer replaced two oxygen sensors (based on their best guess). Car operated satisfactorily for 60 days; now experiencing sputtering and stalling again.