I'm buying a downstream O2 sensor from Rock Auto and they are "suggesting" that it is best to replace both up and downstream together. Is this true?
FWIW I searched for thread titles that contained "O2" and/or "sensor" and then read the O2 ones 9 pages in on the search results. That was about 20 threads worth of O2 Sensors (yawn). They were all about brand names to buy, troubleshooting, location, removal tools, blah blah.
And FWIW part deux the reason I'm buying downstream is I got the fault code several times. Have tried cleaning contacts in the connector, inspected condition of wires, cleared codes and every time the code came back after another 100-200 miles. (At least I got it to stay off long enough to pass Calif smog!) Car has about 130k on it.
Thanks for any advice guys!
