Hey guys, has anyone ever had to replace their o2 sensors? I've heard that a fouled o2 sensor can affect your gas mileage. Is there any way of checking them? I checked to see how much they are and found performance nissan listed 3 different o2 sensors at 99.78 EACH! Do each of the sensors affect fuel economy? If I were to replace these would I have to replace all three?

 

i replaced two o2 sensors from my 92 lexus and fixed the CEL problem...there are a total of four o2 sensors....two before cat and two after cat. i only had to replace the two sensors before the cats. Normally the two after cat sensors tend to last a little longer. i also replaced all four o2 sensors in my wife's 99Mercedes when the CEL came on.....those sensors retailed for over 150$ each. You can pretty much replace the sensors on your own with the right tool.