So, I am not sure where to go right now.... I did some research here on P0150, 171, 130 & 134 which all pointed to the O2 sensors. I have an ultra gauge, and it too said these codes plus the system was running open loop.

I ordered new O2 sensors (Bosch) from Rockauto and installed... initial results GREAT truck ran smoother and the Ultragauge showed closed loop and no codes

BUT - now showing P0150 and open loop again??!! Did the sensor go bad? OR am I missing something else?

Couple weird things, the UG shows 0 volt on all sensors at time and just in general goes all wonky on O2 sensor readings from time to time. Is there a computer issue? Maybe wiring (as when it heats up the issue is more consistent, so far). I checked the wires as best I could... as they run behind the heads / valve covers BUT no chaffed wires that I could see.... ugh!

Appreciate any insight, thank you.

 

Try twisting and pulling on the wires while reading the o2 values. My buddy has a similar issue and the wires were damaged inside of the plastic harness cover.

He ended up splicing in at the ECU all the way to the o2 sensor to eliminate any issues.

 

I have done some more Diagnostics, see attached for live data showing the O2's and their output. I will try Abran's suggestions and update here. Thanks for the help.

 

Ok, went outside and applied dielectric grease and inspected the wires. No issues... however while doing the inspection, I notice that the manifold looked cracked

Would that effect the sensor? It may be leaking / introducing gases causing bad readings. This may be an issue??? I would have thought I would have noticed some symptom. Have a look at the attached photo, it shows what I think is a crack...

Appreciate any input, thank you.

 

I'm guessing it would. Are the faults/abnormal readings on that side?

 

Oh man, that sucks! That could definitely cause some weird readings.
What about your MAF reading? I'm not sure about the "lb/s" measurement the scan tool is using. My scan tool reads out in inches of mercury. But 0.01? Seems like a low MAF reading, which can also cause bad o2 readings. At idle, on my scan tool, it usually runs around .50 hgi. Maybe try a few wide open throttle snaps and make sure you get a good spike at the beginning of the throttle snaps. Again, I can only tell you what my scan tool gives me for readings, but on a throttle snap it spikes to about 5.00 or higher if the MAF sensor is good.
I hope this helps you.
Good luck!

 

Ok, so went out and did some more Trouble shooting, I swapped the B2S1 with B1S1 and it worked for a few minutes. BUT now BOTH are not working. Thinking short cct - trying to figure out the RAV electrical manual… found the cct but it doesn’t tell me where those wires go to. HELP pls…

I am going to drive it this way for now… grrrrr! I thought I was close to fixing it. Seems like a little more to it. How frustrating!!!

Really appreciate any help - what should the next step be?? I am thinking go to the wrecker and pull the wire harness for the B2S1 side and splice in a new one on mine…
But how much work will that be. AND I need to get new sensors

ARGGGHH!

 

So the EPIC saga continues.... I am getting the feeling that the Rover hates me I have trouble shot the O2 system... and there are several items that confuse me. I have done:

confirmation of harness (resistance checks)
swapped O2 sensors from side to side... to ensure fault doesn't follow
computer (initial thoughts was ECU) swapped
new sensors all around

I still have the problem!! So back to the start I guess. I def have a crack in the exhaust manifold, but not an issue at the moment.

Really would appreciate anyone's assistance with this... if you have had experience with a bad O2 sensor or cct... pls let me know.

Thank you.

 

Bump... looking for any experieced O2 techs