I had been intermittently getting a check engine (solid) light. It read P0042. Finally it stayed on long enough to take it in and they are replacing that sensor under factory warranty. I also have an extended (non factory) warranty. While in the dealership they video my car and show me another O2 sensor that is frayed and wires fully exposed in a section claiming it must be from a rodent. I have an epoxy garage floor and my floor is spotless. I have never seen a mouse dropping. Regardless the dealer wouldn't replace it without a charge which I passed on at the moment for 2 reasons; first it isn't throwing any codes but secondly the dealer quoted me almost $900 to replace the O2 sensor. First off I know they are easy to replace but isn't the cost to buy the O2 under $200? I get floored when I see what dealers try to charge customers for repairs. Literally once you have access to the sensor it is like a 20 minute job.

 

I'll give you what I know. If you buy the 02 sensor from JLR then you are looking around $300 per sensor. If you look online or go to your local car store, they are a good bit cheaper. I have found they are in the $110- $150 range for the OEM sensor. This price also depends on which store you go too as they vary greatly in price for some reason. I have been looking around so that I can replace one of mine as well, but it seems the one I need has to be special ordered. I might just go on Amazon and order the sensor? As for the replacement, it is fairly simple and quick. I think mine took maybe 30 minutes to do and that's counting the time needed to find a lost tool.