Check engine codes p0136 and p0138

So i still have this problem on my tacoma... but i no longer have the p0136 only the p0138.

I know to 02 sensor is not the problem cause i got two of them that do the exact same thing :

they stay at around 0.835 V and don't move much. When i release the throttle they go down to around 0.15V and slowly go back to 0.835V.

I only get the p0138 code when i ride at the same speed for around 2-4 minutes because the sensor output is around 0.835V.

 

Did you do anything I suggested earlier in the thread? Upstream o2 sensor replaced yet?

 

your a/f sensor is bad and its thinking the 02 sensor is bad cause the af sensor is giving the wrong readings. if you have a high voltage code start with the af sensor first

 

I ordered one and will try it! I will keep you guys tuned!

Thanks

Jstem4

 

Hey guys, so i ordered a air fuel sensor (bank 1) from ebay. The guy i bought it from said it was the Denso 934-9050 but when i received it today I founded out that the sensor is actually a 89497-07040. Will this sensor work? Why is it so much cheaper than the 89497-04050(tacoma 2.7 Oem) ?

Can this break anything in my truck?
Should i install it or just return it to buy a 89497-04050?

thanks jstem4

 

Hey guys,

I received my air fuel sensor and installed it. I did not get the code back yet, it's been a week. I Guess that was my problem, the front air fuel sensor.

Thanks a lot for your tips!


But I noticed something weird on my 02 sensor(bank 1 sensor 2). When the truck is all warmed up at idle the output voltage stays at around 0.835v. It does not fluctuate. Even sometimes when i drive the output voltage stays at a reading without moving, and sometimes it works correctly. I am guessing the this sensor is also bad, but i just replaced it with a new one 8 months ago. Maybe i destroyed it with running the truck rich for all that time?

Can it be something else or is it the 02 sensor?

Thanks for your help !

Jstem4

 

It could be that running it rich ate the second sensor, but it's unlikely. It isn't as smart as the front sensor, if there are no codes just drive it. All the 2nd sensor does is make sure your cat is working. Here is how you can check it before you replace it again- http://www.customtacos.com/tech.old...6toyrm/06toypdf/06rmsrc/rm2006ta/01200810.pdf

This one does a good job of explaining how it all works.
http://www.customtacos.com/tech.old...06toyrm/06toypdf/06rmsrc/rm2006ta/0060026.pdf

 

Maybe my cat is toasted? I've been running for a long time with a bad air fuel sensor...

 

I doubt it, they are pretty tough. I ran leaded race gas mixed with two stroke oil in my truck once, cats were still ok.

 

Yes, where did you read the temp?

 

The voltage should vary from 0 volts to 1 volt and be pretty active. Running rich should not damage it how do you know it was rich?