P0158 Check Engine Light

Hello,
I have a 2005 toyota tacoma 6 cylinder 4x4 that I just recently purchased off a private party. I am getting a P0158 code as well! I just replaced both downstream o2 sensors, ignition coils, and spark plugs (used all denso oem parts). I checked the resistance across the o2 sensors and they read around 16 ohms at 90 degrees Fahrenheit(means they're good). I logged both downstream o2 sensors and found out that sensor corresponding to bank one would have a voltage that varies. o2 sensor correspding to bank 2 holds at a constant voltage (around .9 volts)I will post pictures to show this. Does anyone know where else I should go from here as far as diagnosing goes?

 

Dude thanks for the fast response I will try this!

 

Yeah that didn't work the wiring harnesses don't match up.

 

I performed the maf sensor test on my sensor and it passed. It registered with 0.65g/s after I drove it around following recommended dealer driving pattern. I also checked the resistance across the wire harness to the ECM and got 1.8 ohm resistance.

 

I found this link that is talking about "fuel trim". https://www.obd-codes.com/faq/fuel-trims.php
I checked out the fuel trim on my truck and it looks like bank one is acting normal. Bank two LT is indicating a 20%. This makes me think that it may be injectors.

Anybody familiar with diagnosing via fuel trim?

 

Code P0158 is for high voltage on Bank 2 Sensor 2. I would consider the possibility that if you just replaced it for the same code as before that you have a possible electrical short in the harness, or bad ECU. What is the voltage reading with the key on, engine off? What is the voltage with the sensor disconnected?

 

Hey sorry for the really late response. I checked the resistances of the terminals for the ecu and they corresponded to the factory manuals specification. I have been driving it like this since back then and now I am getting a constant misfire on bank 2. P302 code... Any ideas?? I'm thinking maybe the cat is toast now since I have been driving it at a rich condition for a while now.

I did notice that I am losing coolant at a really slow rate. I'd say couple liters every few months. Think maybe the head gasket could be toast??

 

I would certainly address the loss of coolant before I did anything else. If coolant is getting into the cylinders and burning off, then that will cause severe fluctuations in AF and O2 sensor readings, as well as misfire issues.

 

Good to know I am thinking I will just take it in and get a professional diagnose. I am done just throwing money at it here and there. I have purchased an installed: plugs, and coils in my garage and it lasted until now.

Keeping my fingers crossed that it's not the head gasket. If it is I think I might just get a whole new block since the labor will be so high and my motor has over 200k miles on it. What would you do?

 

At 200K you are at that balance point between rebuilding and replacing. It all depends on your budget. If you do get a replacement block however I would strongly suggest getting a long block with the heads already installed. Saves a lot of time and money, and gives you a set of heads that are reconditioned.

 

Just had another p0158 at work. Af sensor bias .3volts. This is not an uncommon code.

 

Ok so i just installed a rebuilt long block and got a 3 year unlimited mile warranty. No more p0300(misfire) but still got the p0158. I was told my catalytic converter is bad. Another member tacotruck422 is claiming an afr sensor. I guess I can try that. I brought it to toyota before I did the motor swap and they said it was the head gasket.

 

I forgot to mention that I replaced Bank 2 Sensor 2 and Bank 1 Sensor 2 02 sensors prior to the engine swap. I also replaced ignition coils, and spark plugs.

 

Is the HO2 sensor heater the A/F meature?

 

This should help diagnose your P0158

 

Thanks Mehullica for this file appreciate it.

 

Hey everybody

Just did the continuity check on the wires corresponding to e5-5 and e5-33. I plugged in the multi-meter probes into 1 of each of those aforementioned tester connections (specified on page 804 in the pdf I sent you and ) and connected to the corresponding wire that connects to the o2 sensor(bank2 sensor 2 post catalytic converter) and got a ring. So now I know the following:

Good o2 sensor(bank2 sensor 2)
Good wire from the ecu to the o2 sensor(there is no break in between)
Brand new long block so good head gasket

What would you do for further diagnosing?


Regards,

Tom Bernard

 

Wanted to share my experience on my troubleshooting.... 2011 toyota tacoma 200,000km. P0158 code came on which is bank 2 sensor 2- high voltage.

So I'm like easy change bank 2 sensor 2 O2 sensor. So I changed it brand new sensor denso.... no change. Plugged in my code reader checked out all my O2 sensors and they were roughly giving out the same voltage and amperage and same codes still remained.... ughhhh.

Went to my mass airflow sensor and cleaned it with mass air flow spray and also took off my throttle body... cleaned that really good with the same spray... it was dirty and black.

Started it up and boom, didn't even have to clear the codes with the reader... they cleared automatically.

Hope this helps
-jilly