I just picked up a 2003 disco and the previous owner had new cats installed and the people who put the cats on cut out the precat O2 sensors and cut the wires (yeah retarded i know and i'm quite pissed). Anyone know if i purchase one O2 sensor and hardwire it into the factory wiring for both left and right side sensor wires will that work or do i have to have 2 seperate o2 sensors. My thinking was that aslong as both sensor wires are recieving the same info and it's a good reading then using one sensor could work and save me a little time and money. Thanks and lemme know what ya think.

 

Is the check engine light on? Any codes?

 

You have to have all 4 02's for the engine computer to do its job, other wise you will have air/fuel imbalance issues

 

If you don't wanna get 6mpg you need both of them. I am speaking from experence cus my pre cat O2 is out on my drivers side. Put two of them in, you will save the extra $70 in gas in no time.