How often should I replace the oxygen sensor in my 1994 buick regal sedan?
Replace your O2 sensors when you put in spark plugs -- hopefully that is at least every 30K to 50K or so, but i have seen people get by going to 100K or more
There is no service interval for o2 sensors, when they go bad there bad unless you want to replace them randomly and yes would do ever 50k or so.
Search Buick Regal Questions
Buick Regal Experts