Before doing a deep dive into P0136, what was the other DTC from the scan? Your photo of the scanner screen shows (1 / 2) Stored, which means code P0136 is one code of two codes stored in the ECU. We would need to know both codes to be able to help you. Focusing on a single code while ignoring the other will likely not resolve the problem.

 

What are the consequences of driving car with check engine light on (P0136)?"
No consequences of importance other than not passing a smog test.

The warning on the scan tool for the P0136 isn't justified as far as causing any damage to your engine.

 

Thanks for weighing in. Good catch. I would have added these.

Even though my photo of the scanner screen shows (1 / 2) Stored , but it listed P0136 twice in scanner screen

Toady, I did the scan with ELM 327 + phone OBDII reader. It showed same P0136. I went to another partstore to confirm, the code reader there printed twice P0136 with same description

"P0136 - O2 Sensor Circuit Bank 1 sensor 2 "

I am not sure, why part store code reader doing this. Other folks can chime in on this topic.

Thanks for your guidance.

 

"P0136 - O2 Sensor Circuit Bank 1 sensor 2 "
Are there any steps/diagnostics to do and confirm the issue are coming from O2 Sensor?
I see some threads in google search suggests cleaning O2 sensor, patching Exhaust leak may fix this issues.

If your O2 sensor has more than 100k miles on it then its probably worth replacing it as a matter of course. They live a very hard life in the exhaust stream and tend to start going off after that many miles (though sometimes they can go longer until throwing a code).

Checking your exhaust for leaks is a very good idea, as an air leak upstream will throw off its readings and make the ECU throw this code. You can make your own smoke machine (youtube) and attach it to the end of the exhaust pipe and look for any smoke coming out anywhere along its length, or pay an exhaust shop / mechanic to do it for you.

Not sure what "cleaning O2 sensor" really is, as they are located in the exhaust. Some sensors say they will be damaged if put in contact with cleaners / solvents.

 

...also, check the wire from the O2 sensor to where it connects to the Engine ECU behind the glovebox to make sure there's no break in that wire along its length (use an ohm meter, unplug at both ends and confirm the resistance in the wire is not high).

 

It's probably setting an active code and it is intermittent, so it is also setting up a pending code. That is the only reason I can think of for the same code to be present twice in the ECU.

While the code talks about the O2 Bank 1 Sensor 2 Circuit, it is most likely the O2 sensor itself. Probably best just to replace it.

 

Thanks for weighing in.

It's probably setting an active code and it is intermittent,

While the code talks about the O2 Bank 1 Sensor 2 Circuit, it is most likely the O2 sensor

How do we conform/test, whether this one is intermittent or not ?

I see O2 Bank 1 Sensor 2 Circuit refers to O2 sensor downstream (After catalytic convertor) . I find many OEM partnumber for this part. I am in Northeast.

What is the correct OEM part for 1999 Toyota camry 4cyl vehicle?

What is the site lookup provide this info?

When I did a search about these issues, I found :

Common Problems That Trigger the P0130 and P0136 Code Defective Oxygen Sensor/Air Fuel Ratio Sensor Defective Oxygen Sensor/Air Fuel Ratio Sensor Heater circuit Exhaust System Leak Intake Air System leak (including vacuum leaks) Low Fuel Pressure Defective Engine Coolant Temperature Sensor Defective sensor wiring and/or circuit problem PCM software needs to be updated Defective PCM Common Problems That Trigger the P0150 Code Defective Oxygen Sensor Faulty Oxygen Sensor wiring or connections

This is crucial to the sensor operating efficiently because the sensor needs to warm up so that the ECM can help the engine reach closed-loop operation. Under closed-loop operation, the engine will receive cues from the ECM as to the specific air/fuel ratio needed to operate efficiently.

The ECM continuously monitors the oxygen sensor’s voltage and determines if the exhaust is running lean or rich and will continue to adjust the fuel injection system to make sure that the engine’s air-to-fuel ratio is optimal for peak performance. While the primary sensor is tasked with adjusting fuel trim, the secondary O2 sensor is monitoring the catalyst’s performance during this time and the readings from Sensor 2 are vital in this operation. So the P0136 and its related codes can also be tied to the catalytic converter and its performance and is why they are important codes to note and know about.

The above narrative point to many issues causing rich/lean fuel mixes triggering P0136.

What are the ways, we can rule out none of the above , but only O2 sensor triggering P0136?

In some threads , I find folks talked about repeating P0136 code reader even after replacing O2 sensor.

How do I make sure O2 sensor is the culprit for my code P0136 ?

Thanks for your guidance.

 

What is the site lookup provide this info? ... In some threads , I find folks talked about repeating P0136 code reader even after replacing O2 sensor. ... How do I make sure O2 sensor is the culprit for my code P0136 ?

I agree with 93celicaconv: The next step is to replace the rear oxygen sensor with the correct OEM one or Denso one. Here is why:

If P0136 is the only code (and you say it is), then from experience and the Toyota service manual three possibilities exist --

-- Bad rear oxygen sensor.

-- Bad wiring. From experience, this is unlikely. But if you know how to use a multimeter, then this may be worth checking.

-- Possibly over-sensitive detection electronics. This is not worth considering until the sensor has been replaced and there is no improvement. This is not in the service manual.

I think every person with a car problem wants the cause "pin-pointed." But I believe the more experience one gets, the more one understands "pin-pointing" is often not possible without highly expensive test equipment; expertise; and sometimes, a fair amount of time and effort.

Sometimes one does have to buy parts and go through a process of elimination. On a 25-year-old vehicle, "firing the parts cannon" is often not a bad idea. If this is the original rear oxygen sensor, its life is over or likely nearly over. Buying a new one is a sound investment, in my opinion, even if the new one does not fix the code.

The sites I use to identify Toyota parts and their part numbers are:

ToyoDIY.com (no drawings, but fast).

http://japan-parts.eu/toyota/ (has drawings)

 

I don't know the details of your particular scanner. On my Innova scanner (it's a high-end unit), using the down-arrow key, it steps through each DTC recorded in the ECU, and tells you if it is an active DTC or a pending DTC. I don't know if your particular scanner has this same capability or not. You can check to see if it does.

A Bank 1 Sensor 2 on a 4-cylinder engine (which only has bank 1 in most cases), sensor 2 is the rear sensor. Per the diagram below, the Toyota OEM part number for your rear oxygen sensor is 89465-06020. Note that on your car, the rear oxygen sensor wire pigtail has a grommet on it as it passes through the floorboard, and the connector end is under the carpeting.

The rear oxygen sensor has no effect on fuel control on your car. It's only purpose is to monitor the efficiency of your catalytic converter. DTC P0136 is not telling you that you have a problem with the catalytic converter. P0136 is telling you the ouput from the rear oxygen sensor is no longer readable by the ECU. That could be a wiring problem. But it most likely is caused by a deteriorated oxygen sensor.

My recommendation to you is to get an OEM Toyota oxygen sensor (if that part number is still available). Otherwise, get s Denso oxygen sensor that is an exact fit for Toyota P/N 89465-06020.

 

Thanks for weighing in.

I did check the exact fit for Toyota P/N 89465-06020 with various price points. I find dealer price shows high end.

Where is the place, we can get this one for reasonable/fair price?

Are there any fakes part with Denso brand to aware about ?

For my own understanding, I like to do Bad wiring testing. I know, how to use multi meter. I'm trying to test for resistance between the pins for the heater circuit to diagnose a P0136 trouble code.

Are there any videos/steps to guide me the process?

What is the best OBDII android app to use with ELM 327 ?

I did see the following during my internet search, I like to share with Forum.

Cleaning o2 sensor without removing it/Cleaning oxygen sensor with carb cleaner/TOYOTA Camry 2017

Diagnosing O2 Sensors

What do you folks think about above videos?

Thanks for guidance/learning.

 

I attach the service manual diagnostics section for P0136 and the relevant wiring diagram for checking wires. I say: Do not venture outside the areas of what the diagnostics procedure says will cause the computer to throw the code.

Ebay often has genuine Denso oxygen sensors that are equal to the OEM sensor. Densoproducts.com can help confirm which Denso sensor a Camry needs.

Yes, stay alert to counterfeits. When in doubt, write the eBay seller. So far I had one counterfeit Denso sensor sent to me by an eBay seller. The seller was good and refunded me everything.

Try whatever with videos, but if they do not hew pretty closely to the service manual, then I for one am not interested.

Mostly be aware that front and rear oxygen sensors do typically fail before the life of a car is over. I am at the point of saying the front oxygen sensor should be replaced as part of routine maintenance after say 200k miles, if it lasts that long. (It should last at least 100k miles and ten years, ball park.)

 

Thanks for your help/suggestions.

I did the scan with ELM 327 + phone OBDII reader for O2 sensor reading. I am attaching the reading for review:

O2 sensor Bank1 sensor 2 shows flat line.

How do I interpret the above graph ?

Thanks for your guidance.

 

You interpret the graph, as shown.

You have confirmed the B1S2 sensor is not responding.

Follow the diagnostic steps that Elle_Rav4 kindly attached to post # 12 above.

In short, if the wiring & connector are good - replace the B1S2 sensor, located underneath the vehicle.

And check the exhaust front pipe for any leaks, etc. while you are there / and fix as needed.

Hope the repair goes well.

 

You have confirmed the B1S2 sensor is not responding.

The B1S2 O2 sensor should be showing a flat line response, as there should be nearly zero oxygen downstream of the cat if it is working properly.

 

Thanks weighing in.

The Check engine light went off after few weeks. I am watching, whether it showing up .

What is the cause?

How to go about in this situation ?

OBD II reader is not finding any ?

Both O2 sensor graph in OBD II is not flat now.

Thanks for your guidance.

 

Thanks for weighing in. Here is what I see the chart in torque OBD II.

How do we determine cause of P0136 code ?

What is the reason O2 bank1 sensor 2 shows differently ?

Thanks for guidance.

 

BMR is correct is saying the output of the oxygen sensor in Bank 1 Sensor 2 should be flat or nearly flat, but the voltage of that flat line should be about 0.45V. Your B1S2 chart is post #13 clearly shows a flat line voltage of zero. A properly working O2 sensor circuit will not go below 0.1V. In your post #17, B1S2 is generally at 0V with some blips going higher.

What to make of this? From looking at the post #13 chart for B1S2 only, I would say you have a faulty wiring circuit since there is no voltage being read at all. But post #17 shows a chart for B1S2 having some voltage output. That tells me the wiring is probably good. The sensor itself cannot be good then, because it should not go below 0.1V (but in both charts, it does). Doesn't mean that your CAT is good, but most likely the B1S2 O2 sensor is not good, the wiring is good, and the CAT condition is still unknown (and will be until a good working B1S2 O2 sensor is in place.

My 2 cents worth.

 

At this point. .after nearly half a year... you should probably just replace the sensors or leave it be. .