Hello everyone, I recently had a few codes related to my O2 sensors on my 2004 discovery,. the codes were: P0150, P0174 and P01174. I then proceed to order 4 new O2 sensor (mid range quality) and replaced them all at once. The two downstream ones are working fine at around 0,445 volts, but both upstream ones show a voltage of 0,445 volts at cold start and drop to 0,000 volts a few seconds after starting the vehicle. I then get P0130 and P0150 (obviously), before changing them my bank 1 sensor 1 was working fine and my bank 2 sensor 1 never got above 0,010 volts. Knowing that the previous ones were showing a voltage and the new ones are showing one at the start I don't think it is a problem with the wiring. Also, this is the second set of upstream O2 sensors (different brands) that I try and both are having exactly the same issue. Do you have any clue of what this could mean?

 

Put the upstream one that was working back in, see if it works. If it does, move it to the other side, if it works on that side you have bad sensors. If it does not you might have plugged injectors.

 

Both were damaged during removal they are not in working condition.. Don't know if it means anything but both upstream and downstream sensors look identical but I see in the rave manual that they should look different..

 

The plugs are different, one is female and one is male.

 

I was referring to this (min both look like the 11 instead of looking like the 12)