Hello everyone. I just bought my first Land Rover, 2002 Discovery 2, and I am facing my first problem trying to find the solution. I was originally getting two codes P0130 and P0171, getting 0 volts to both o2 sensors.. I replaced with new Bosch’s and now one works but the front passenger side (US) is starting with voltage then dropping to 0 in the first minute or so of start up.. also P0560 popped up once.. seems like the system is still running rich although not as bad but still $60 every 5 days in gas seems like a red flag for how minimal I drive! I can’t figure out what’s wrong I think it might be an electric issue? Previous owner said service engine light popped on right after he was spraying/cleaning the engine with a hose (why? Smh) but that’s what triggered this whole situation. Any insight would be a HUGE help, thanks in advance!

 

You gotta provide way more info. Your car is 17 years old, without knowing what has been done to it, it is hard to say what could be causing the issue. Bad O2 sensor, an issue that happens an upstream that fouls the sensor, etc.

 

@DiscoveryWes O2 sensors generally should be changed out in sets, you do both on one side. It is hard to tell from you post if you did just fronts, just rears or a combination.

Bad sensors out of the box are not unusual

These trucks are not good on gas - you have a 25 gal tank and will get between 250 and 300 miles to a tank depending on how the engine is running.

You need to start with basics:

Why do you think it is running rich
Double check your o2 sensor plugs are they tight
What grade of gas do you run - in North America 91 is the recommended
Have you checked the air filter
Checked all the vacuum lines