Originally Posted by jr's3800
With any high milage car that has an Original O2 you can bet that it has slowed some in its signaling rate.... we reccomend that they be replaced at 50-60K intervals too keep the effiency up... I have never had one that lasted more than 70,000 miles... If you gas milage was to take a sudden nosedive for no reason than the O2 would be suspect to failure...
Wow, 50-60k huh? Whose reccomendation is that again, I saw you said "we"? You can PM me if you dont want to disclose it to everyone. Are you saying the o2 sensor can change the rate that is signals the computer? Its readings may become very low/high, it may flatline, it may totally DIE... but I never knew the rate at which it samples wasnt determined by the computer.
O2 sensors last over 70k all the time on the average car, and actually on the average car 90-110k is the expected life span. Changing them earlier as preventative maintenance is ok, just as long as you realize that youre more than likely to replace a good part. If your car has had some other problem such as a leaking down injector, excessive oil burning, blown head gasket, etc then you should expect your O2 sensor to last nowhere near as long. OBD cars are very capable of letting you know when to replace your O2.