Please Help Trouble Codes P0137 & P0158 OBD Fusion Diagnostic Report

Hi, I've been testing out the OBD Fusion app due to the trouble codes. I cleaned my MAF sensor , changed both A/F and O2 sensors with Toyota ones from the dealer but I'm still getting the 2 trouble codes. I'm attaching the diagnostic report from OBD Fusion and was hoping anyone with the same model vehicle can compare reports and point me in the right direction or if something doesn't look right please point it out. I'm also adding images of both O2 sensors while driving and something doesn't look right. Picture with 6 is cruising on 6th gear above 60mph and the one with N is at Neutral at a stop light. I've read it could be my cats but shouldn't I get the error code for that? I'm trying to use as much information I can from OBD Fusion before taking it to the shop and getting hosed. Thank you.

 

I’m not an expert but did you clear the codes first? Disconnect the battery for a bit?

 

Yes, each time I made any changes like clean maf sensor, replaced A/F & O2 sensors I would clear the codes with the OBD Fusion app but they come back after 40+ miles of driving. I'm hoping someone with the same model vehicle can run their diagnostic app and compare what it looks like when all is working.

 

P0137 02 Sensor Circuit Low Voltage (Bank I Sensor 2)
P0158 02 Sensor Circuit High Voltage (Bank 2 Sensor 2)

 

Both sensors are indicating one is running rich and the other lean. I don't understand why is that, if my A/F sensors monitor the mixture and no error codes there, then it goes through my cats and out the post cat and thats where my O2 sensors are indicating the mixture is not right based on the graph images and error codes. Am I missing something here. Just trying to make sense of all of this. Appreciate the help.

 

Is it possible you got the harness connectors backwards when plugging the sensors back in?

Sounds silly, but I've seen this on too many vehicles to count now. Domestic, Euro, and Asian brands. The ECM/PCM sees B1S2 (bank1 sensor2) and thinks it's B2S2 (bank2 sensor2), because the connectors are swapped. I've seen techs do this, as well as DIYers. When manufacturers use the same connector for multiple sensors and put the harness connections close to each other, crap like this can happen.


TL/DR - go outside and swap the O2 sensor harness connectors around, clear the codes and report back.

 

Just checked the connector locations...yeah, it's totally possible to swap the B1S2 and B2S2 connectors.

 

So what you are saying is to switch the sensors around? Got it. I'll try it and report back. Thanks for the tip

 

I don’t think he said to change the sensors, just swap their connections from the harness..

 

Correct

 

I’m sorry I forgot to mention I am far from being a mechanic sorry for the dumb questions but how exactly am I suppose to swap the connections from the harness? Are you saying I have to cut the wires or is this a plug and play setup. The female end of the connector looks to be hardwired back to the harness.

 

There's nothing to do but unplug both O2 sensors and plugging them back in but; plug the left sensor into the right harness, and plug the right sensor into the left harness.

Then clear the codes, and go for a drive.

 

Understood! I’ll be reporting back shortly. Thank you.

 

Just got back from Santa Barbara with no CEL which means your tip worked. Thank you for the help, really appreciate it.

 

Man, that was a close one...

Good job @blu92in99
Good job @Charlie213 - congrats on the fix

 

Yeah, I over think things too much and always assume the worst. Appreciate everyone’s help.

 

Haha, just had this same crap.. was using my scan gauge saw the st and Lt fuel trims opposite as well figured I screwed the damn sensor orientation up, this helps maybe confirm that.

question I’m going to be hunting now is what’s the science of is the o2 sensors being swapped.. like does it bring the system into open loop and end there? I recall the AF sensors being meaningful in the AF ratio of these engines, but the O2 sensors being only meaningful to the health of your catalytic converters (which don’t exist in my truck

 

I believe my mechanic made this same mistake. Are the B1S2 and B2S2 connectors located under the fj or accessed from the engine bay?