Hello everyone. I have been trying to tackle p0130 and pO150. I recently replaced all 4 sensors and my bank 2 side are both goo and operating fine. My oxygen sensor bank 1 upstream and downstream show zero volts. I first started by clean all the bank 1 connectors with electronic cleaner (since I did seen some oil in the connector prior to installing the new o2 sensors) the weird thing is when I disconnect the upstream o2 bank 1 sensor the downstream bank 1 sensor shows voltage?? But when I connect the upstream sensor back in the voltage drops to zero for both downstream and upstream bank 1 sensors. My next step was going to swap the upstream side to side and see if anything changes if that doesn’t work then maybe buy all 4 Bosch. Why do you guys think the voltage drops when I unplug the upstream sensor?

 

Swap left to right and see what happens.

 

I swapped left from right and rulled out the o2 sensor works. When I swapped the passenger side to driver side the sensor was showing working. On the sensor 2 bank 1 and 2 were working. But the ones that worked for sensor 2 did not work on sensor 1 side (bank 1 and bank 2). I know if I unplug sensor 1 bank 1 then sensor 1 bank2 has voltage and shows working. I do not understand why sensor 1 bank 1 affects bank 2 when I have it plugged in it drops bank 2 voltage to zero. So right now even swapping side to side my sensor 1 bank 1 and 2 are both showing zero volts

 

You have a lean condition on that side, unplugging the front sensor sends it in to a mode where it uses rpm and MAF reading to fuel, not sensor input. Any other work done recently? Typically one bank only lean condition is leaking intake tract, usually loose intake manifold bolts or perhaps injector o-rings. Both are typically an idle only condition i.e. at highway speeds the sensor comes back on because enough air and fuel is being used that the leak is inconsequential. Also possible it is a partially plugged injector which can be tested by swapping all injectors left and right.

 

I recently bought the car a few weeks ago. Only think I have done was replace fuel pump and cross my fingers head gasket isn’t slowly leaking lol(which I’m about 90% sure it is.) I just wanted to solve this o2 problem before tackling the head gasket. I was going to get new spark plugs and injectors. Do you think I should rule out the head gasket first? (Will this contribute to the problem, I would hate to get new sparks and plugs and let them get worse from the head gasket issue?). I was going to buy a volt meter to test the upstream connector but I think that’s a waste of time because I did see a slight voltage at the upstream bank 1 sensor at one time. Thanks again for the direction guys.

 

Ok, give you recently bought it and do not have service history I am going to guess they recently did some service on it and it has a vacuum leak. Tighten all the intake manifold bolts on the side with zero volts and if that does not fix it remove the injectors and have a close look at the injector o-rings. If they are damaged they can create a vacuum leak. Have you tested it on the highway to see if they work at highway speed? Is it using coolant? Are there a ton of bubbles in the coolant tank when running? A leaking hg that is causing the engine to drink coolant will kill the 02 but it takes a little while and you just replaced them so I doubt that. Suggest you run the cap one turn loose while you are in diagnosis mode, read this post: https://landroverforums.com/forum/di...46/#post887409

 

Ok I will try a few of these and get back to you. Busy with work and the kids but hopefully I will get time later this week if not Sunday. Thanks again.