Toyota P0136 or P0138? (TOP 5 Tips)

Toyota Year: 2016 Recently had to look at a Prius which had error codes P0136 and P0138. These codes relate to the rear oxygen sensor, P0138 indicates high voltage. Normally you would expect the sensor to be fault and needs to be replaced however in this case it was the upstream sensor at fault.

  • Trouble codes P0136 or P013 are a fairly common problem on Toyota. Toyota has issued a service bulletin T-SB-0001-10 to address the P0138, P0158 or P0606 issue. The bulletin applies to the vehicles listed below.

How do I fix code P0136?

What repairs can fix the P0136 code?

  1. Replacing the O2 sensor for bank 1 sensor 2.
  2. Repairing or replacing the wiring or connection to the O2 sensor for bank 1 sensor 2.
  3. Repairing exhaust leaks or a damaged catalyst.

What does Engine code P0136 mean?

What Does P0136 Mean? Your car has oxygen (O2) sensors that measure the amount of oxygen present in your exhaust. If you are seeing code P0136, it means that the O2 sensor behind your catalytic converter on bank 1 is malfunctioning.

What does Engine code P0138 mean?

When trouble code P0138 is set, this indicates that there is a high voltage (steadily above. 9 volts) for more than 10 seconds indicating a lack of oxygen in the exhaust stream and an abundance of fuel at sensor 2 on the bank 1 of the engine.

What causes O2 sensor high voltage?

The high voltage condition from the O2 sensor is indicating a lack of oxygen in the exhaust or other related problems, such as a leaking fuel injector or a broken up catalyst inside.

Which 02 sensor is bank 1 sensor 2?

Air Fuel Ratio/Oxygen Sensor Identification A typical in-line 4-cylinder engine has only one bank (Bank 1). Therefore, in an in-line 4-cylinder engine, the term ‘Bank 1, Sensor 1’ simply refers to the front oxygen sensor. ‘Bank 1, Sensor 2’ is the rear oxygen sensor.

Should I replace all O2 sensors at once?

Manufacturers recommend replacing O2 sensors in pairs (both Upstream or both Downstream). An older, slower sensor can cause an imbalance in the engine management system, leading to poor fuel economy and possible damage to the catalytic converter.

What does engine code P0137 mean?

What Does P0137 Mean? Oxygen sensor 2 is the downstream oxygen sensor in relationship to the catalytic converter. When trouble code P0137 is set, this indicates that there is low voltage (roughly 450 millivolts or less) for more than 20 seconds coming from the bank 1 sensor 2 oxygen sensor.

What causes oxygen sensor code?

An engine misfire, leaky exhaust valve or a leak in the exhaust manifold gasket that allows air into the exhaust may also cause this type of code to be set. If an O2 sensor has failed, especially prematurely, the cause often is contamination. Like us, O2 sensors slow down as they age.

Is P0138 serious?

Is Code P0138 Serious? Driving short distances is not a problem when your vehicle shows a P0138 code. Running the engine with a higher fuel-to-oxygen ratio does not cause immediate damage to your vehicle. However, it will cost you in fuel efficiency and can cause your exhaust to be less clean.

Can you drive your car with a bad O2 sensor?

Yes, you can drive with a bad oxygen sensor if you can still start your engine and feel little difficulty driving. But don’t leave it alone for over a couple of days, as it might cause safety problems and lead to the malfunction of other parts of your vehicle.

What voltage should an O2 sensor read?

An O2 sensor will cycle between 0.10 to 0.90 or almost 1 volt. An O2 sensor has to reach the 0.8x Volts amplitude mark while at full operation. An O2 sensor also has to reach the 0.1x Volts amplitude mark while at full operation.

What voltage should downstream O2 sensor read?

The Downstream Oxygen Sensor (Oxygen Sensor 2) Therefore, the downstream oxygen sensor (sensor 2) should produce a steady voltage of approximately 0.45 volts.

Toyota P0136 or P0138

Codes that indicate a problem P0136 and P013 are two codes that appear often on Toyota vehicles. Toyota has published a service bulletin T-SB-0001-10 to fix the P0138, P0158, or P0606 issues. The service bulletin is available here. The advisory is only applicable to the cars listed in the following section. NOTE: There are two types of sensors used in these vehicles: the air/fuel ratio sensor and the oxygen sensor. Although they are both referred to as oxygen sensors, they are actually rather different.

Following the installation of the catalytic converter, the O2 sensor is only used to verify that the catalytic converter is functioning properly.

What the Toyota P0136 or P0138 trouble codes mean

MAIN CAUSES: A short circuit in the HO2 sensor (sensor 2) circuit, an inoperable HO2 sensor (sensor 2), an inoperable HO2 sensor heater (sensor 2), and an issue with the Integration relay (EFI MAIN relay), Leakage of gas from the exhaust system

P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)

CASE STUDY: HO2 sensor (sensor 2) circuit is open or shorted, the sensor (sensor 2) is bad, the sensor heater (sensor 2) is bad, the air-fuel ratio (A/F) sensor (sensor 1) is poor, and the Integration relay (EFI MAIN relay) is faulty. Gas leakage from the exhaust system is also a cause.

Diagnose Toyota P0136 or P0138

It is necessary to have a rich combination flowing out of the cat for the post cat sensor to detect high voltage, or the sensor itself must be defective, in order for the sensor to read high voltage. Starting with a big vacuum leak intentionally introduced into the system, assess the reaction of the post cat sensor to see if it is working properly. This should cause the post cat sensor to register as lean for the time being. After that, cause a wealthy state to exist. If the post cat sensor reacts correctly, this indicates that the air fuel ratio sensor is not effectively managing the air/fuel mixes, which would result in a persistent rich or lean situation in the post cat sensor unless the air fuel ratio sensor is replaced.

  1. The air fuel ratio sensor should be reading between 3.35 and 3.70 volts, and the post cat sensor should be reading between 0.70 and 0.90 volts, according to the manufacturer.
  2. It is necessary to replace the post cat sensor if it fails to respond to a vacuum leak or a rich situation.
  3. An extremely typical DIY error is to automatically replace the post-cat O2 sensor just because it seems to be faulty in the issue code.
  4. Carry out the tests
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Vehicles affected by Toyota service bulletin T-SB-0001-10

Avalon (2005 – 2010), Camry (2007 – 2009), Highlander (2009 – 2010), and Highlander (2008 – 2010).

RAV4 (2006 – 2010), Sienna (2007 – 2010), and others. Venza 2009 – 2010; Venza 2019; 2009 – 2010 Venza; 2009 – 2010 Venza Rick Muscoplat is a professional musician. Rick Muscoplat posted a blog entry on

Check engine codes p0136 and p0138

  • Date of joining: May 23, 2014 Member:130462 Messages:10 Gender:MaleQuebec Toyota Tacoma 2.7L (2010 model) Hello, for the past three months, I’ve been receiving both the p0136 and the po138 at the same time. Both codes are associated with the 02 sensor (Bank1 sensor2), which is situated immediately after the catalytic converter. My vehicle is a 2010 Toyota Tacoma access cab 2.7L 4×4 with 92000 kilometers (about 57000 miles) on the odometer (roughly 57000 miles). At first, I suspected that the problem was with the sensor, so I changed it after the catalytic converter was installed. That didn’t work either
  • Both of the codes are still illuminated. All of the cables appear to be in proper working order. I all, the truck is just 4 years old, so what could possibly be the problem? Is there anyone else who has experienced this problem? Here are some examples of photographs: The first is the dashboard, which has the check engine light illuminated as well as the ESp light. The others are screenshots that I took while using my OBD program to diagnose a problem. When the vehicle is operating, you can view all of the specifications. Aside from that, I took a print screen of the sensor and noticed that when I apply some throttle to the engine while it is in neutral, the voltage appears to drop below zero or remain at zero volts. Is this a usual occurrence? Any assistance you could provide would be greatly appreciated. Thanks Julien


  • Date of joining: May 23, 2014 Member:130462 Messages:10 Gender:MaleQuebec Toyota Tacoma 2.7L (2010 model) Wow, thank you very much. What is this document? It is a diagnostic process provided directly by Toyota that explains how to resolve your issue. It’s possible that the kitties are toast. If you need to pass any form of communist inspection, you may either buy new cats or use one of these to fool the ECU into thinking you have one. I’m not claiming for definite that the cats are evil, but if they are, this would eliminate the need for the regulations. According to federal law, your emissions system has an 80-thousand-mile warranty. You should take it to the dealer and cease tampering with it
  • He’s at that Canadia location.


  • Date of joining: May 23, 2014 Member:130462 Messages:10 Gender:MaleQuebec Toyota Tacoma 2.7L (2010 model) I contacted the dealership, and they informed me that it was not covered by the warranty.


  • Date of joining: May 23, 2014 Member:130462 Messages:10 Gender:MaleQuebec Toyota Tacoma 2.7L (2010 model) Thank you for the link
  • If I am unable to locate the problem, I will investigate this simulator. Are there any methods of diagnosing a sick cat? The codes from your Toyota may be determined by using a ‘advanced’ option on your OBD/CAN scanner, or you can hire a dealer to diagnose the problem.

landphilWishin’ I was Fishin’

  • Date of joining: March 3, 2011 Member:52290 Messages:2,919 Gender:Male Location:BC, Canada Vehicle: Toyota Tacoma DCSB 2006 (RIP). Tundra 5.7 modification Check your owner’s handbook and warranty instructions
  • I’m rather certain you still have coverage for emissions-related components. Do not rely on the advice of an uneducated service writer unless you want to be on the receiving end of the short end of the stick. Heck, you should still be protected by the powertrain warranty, which is good for 5 years or 100,000 kilometers.

HondaGMRoll Tide

  • Date of joining: October 28, 2009 Member:25056 Messages:5,807 Gender:Male James South-Pole is his given name. Vehicle: 2009 Dodge Dakota 4×4 with blown Honda VTEC V8trd exhaust, step bars, vent visors, bed lights, and tailgate modification It’s true that Canada has some HOT ladies

landphilWishin’ I was Fishin’

  • Date of joining: March 3, 2011 Member:52290 Messages:2,919 Gender:Male Location:BC, Canada Vehicle: Toyota Tacoma DCSB 2006 (RIP). Tundra 5.7 modification According to Toyota Canada, you are covered by a limited warranty. If a catalytic converter fails, it would almost probably qualify as a major emission component, if that is truly the source of the problem. The most recent modification was made on May 24, 2014.


  • Date of joining: May 23, 2014 Member:130462 Messages:10 Gender:MaleQuebec Toyota Tacoma 2.7L (2010 model) I found today that the temperature of my 02 sensor never rises above 200 degrees Celsius (392 degrees Fahrenheit). Could this be the source of the problem?

jboudreaux1965Ragin Cajun Fan

  • Date of joining: June 2, 2014 Member:131162 Messages:3,125 Gender:Male JosephHub City is his given name. 2005 to 2012 Front End Mod 3′ 810lb IronMan TOYO50C coils on a 2006 Pre-Runner TRD Sport vehicle. 4′ MaxTrac Spingles are available. Amp Dimensions: 35.6′ x 12.8′ PPro Dodinson front struts and rear shocks for off-road A/T use. Custom 4′ aluminum single piece driveshaft built by Deaver AAL in 2012, interior built by J-VIN in 2009, 1GR-FE Cali Off-road Anarchy PVD wheels in 20’x10′ and other sizes, etc. Lol! If you’re merely concerned with acquiring an inspection sticker or something along those lines, don’t worry about the emissions stuff. In the event that you have an OBD reader, take it to the inspection facility and read the codes immediately before you walk inside. Then choose Reset Codes and have them perform the inspection
  • It will take a time for the codes to register again and trigger any dash lights and other indicators.

KborNew Member

  • Date of joining: January 20, 2015 Member:146816 Messages:2 Nova Scotia is a male-dominated province. 2012 2.7 SR5 Sport Utility Vehicle Hello, I have a 2012 2.7 with 63000 kilometers on the odometer and am receiving just code P0136. I changed the back O2 sensor, however the error code remained the same. Is there anyone who has any suggestions? Thanks, Kevin
  • P0136 indicates that the sensor’s voltage is low and that it is ‘running lean.’ To reset your computer, double-check the connector and the cables that go to it. You may also yank your ecu fuse or battery cord to reset it. If everything checks out, it might be a faulty cat or perhaps the upstream O2 sensor
  • However, this is unlikely.
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landphilWishin’ I was Fishin’

  • Date of joining: March 3, 2011 Member:52290 Messages:2,919 Gender:Male British Columbia, Canada Vehicle: Toyota Tacoma DCSB 2006 (RIP). Tundra 5.7 modification Because of its age and mileage, you are still covered by the manufacturer’s powertrain and emissions guarantee.

KborNew Member

  1. Date of joining: January 20, 2015 Member:146816 Messages:2 Gender:Male Nova Scotia is a province in Canada. 2012 2.7 SR5 Sport Utility Vehicle Unfortunately, Toyota does not provide coverage for O2 sensors after 60000 kilometers. Tonight, I’m going to inspect the connector and wires.

Toyota Corolla P0136: O2 Sensor Circuit Malfunction (Bank 1 -Sensor 2)

Typically, the Toyota Corolla will display P0136 as an OBDII trouble code. It is most commonly triggered when the O2 Sensor voltage is outside of the usual working range of the sensor. Bank one will be the side of the engine that has cylinder 1 as the first cylinder to fire in the firing order.

Toyota Corolla P0136 Symptoms

Most of the time, the sole symptom of P0136 will be the service engine soon light on the dashboard. In certain circumstances, there may be additional signs and symptoms as well. These are some of the signs and symptoms:

  • Engine has a rough idle
  • The exhaust smells
  • The service light is illuminated
  • The MPG is poor.

The majority of the time, there is no danger of a breakdown. However, like with anything that causes the service engine soon light to illuminate, it is a good idea to get it repaired as soon as it is discovered. Driving your car for extended periods of time with the P0136 code might result in engine and catalytic converter damage, among other things.

P0136 Causes: Toyota Corolla

The following are the most often seen problems that result in the P0136 code in the Corolla. They are provided in a sort of descending sequence from most to least likely to be the source of the problem.

  • One of the most common reasons that P0136 is causing your service engine soon light to illuminate is a bad oxygen sensor in the first place. Although it may be tempting to replace it straight immediately, it would behoove you to first inspect the wire harness that surrounds it. See the section just below. They are reasonably priced at places like Autozone or Amazon. Damage to the Wire Harness — The wiring harness that connects the front and rear oxygen sensors is extremely vulnerable to damage. Due to the fact that O2 sensors are located under the chassis, they are prone to damage from road debris as well as a great deal of exhaust heat, this is the case. In particular, the downstream sensor is vulnerable to this phenomenon. On YouTube, you may learn how to locate a short in a wire harness. Deterioration of the Terminal – The terminal (the socket) to which the oxygen sensor is connected is likewise a rather vulnerable component to damage. You’ll want to double-check that there’s electricity flowing to the device. More information about this may be found straight below
  • When there is a leak in the exhaust system, oxygen that shouldn’t be there is allowed to enter. That has the potential to throw this code
  • P0136 – If you are receiving P0136 after recently replacing your Oxygen sensor, it is possible that the replacement was incorrect or defective.

Corolla P0136 Diagnosis

Check out this amazing tutorial on how to diagnose a P0136 problem code, which covers every element of the process. Although it is for a Volkswagen, the code is universal. With the aid of a multimeter, it is easy to diagnose the P0136. If you use a multimeter, you’ll be able to see whether or not the voltage coming to and from the oxygen sensor is within specification. This may help you identify whether the problem is with your Corolla’s O2 sensor or with the vehicle’s wiring harness. Unless you happen to be in possession of a multimeter, it would behoove you to examine the wire that connects to the fuse box and the oxygen sensor first.

Additionally, a voltage test light may be used to detect whether or not the oxygen sensor is receiving any voltage at all (these are available for approximately $5 at Walmart).

Whenever the light illuminates, even for a fraction of a second, you know that you have a short circuit, which is causing the P0136 issue code to appear.


Most of the time, when P0136 occurs, it is the oxygen sensor itself that is to blame for the code being triggered. Good luck figuring out what caused the problem with your Toyota Corolla. If you have anything to contribute, please feel free to do so in the comments section below this post.

Prius Gen 2 P0136 P0138 Dtcs

I recently had to take a look at a Prius that was displaying trouble codes P0136 and P0138. These codes are associated with the back oxygen sensor, with P0138 indicating a high voltage. Normally, you would anticipate the sensor to be faulty and require replacement; but, in this instance, the sensor upstream was faulty. Ideally, when driving, attempt to see whether the downstream sensor is functioning properly by getting some high and low readings to determine if it is operating properly. Another option is to look at the frozen frame data; if the downstream sensor voltage was between 0.5 and 0.9v, it is likely that everything is in working order.

  • It appears that the upstream air/fuel ratio sensor becomes sluggish or out of calibration, causing the engine to run rich.
  • As a result, the downstream sensor voltage remains high and a P0138 is generated.
  • If you do not use the authentic Toyota tool, replacing the sensor will be a little more difficult since you will require an offset sensor socket and you will most likely have to grind the outside of the socket down.
  • According to the Toyota repair handbook, you must first remove the hybrid inverter from the vehicle.
  • A Toyota dealer gave me a quotation for a new air/fuel ratio sensor that was around £220.
  • Instead, I used a Denso OEM device with part # DOX-0262, which can be purchased for less than £100 on the Denso website.
  • However, in this case, this specific sensor is exclusively used for the Prius, and hence is an exact replica of the original sensor in terms of functionality.
  • According to several US forums, this mistake is not rare, and it appears that most dealers are replacing the downstream sensor first, and then the upstream sensor at the second effort to resolve the issue.

Hopefully, this information will be of assistance to someone. The Prius Generation 2 is getting to the point where these kinds of problems are becoming more common.

Fixed my 2012 Toyota Rav4 that had P0136 & P0138 codes present!

The review will take place in the United States on March 2, 2021. The codes p0136 and p0138 appeared on my 2012 Toyota Rav4 2.5L engine, which had 139000 miles on the clock at the time. I attempted to erase the codes, but both codes kept resurfacing, so I decided to attempt to repair it myself. Now, codes p0136 and p0138 direct you to the Bank 1 Sensor 2 O2 sensor for further investigation. The Air Fuel Ratio sensor in Bank 1 Sensor 1 was discovered to be the source of the problem, rather than the Bank 1 Sensor 2 O2 sensor, thus I opted to replace the Air Fuel Ratio sensor with this Denso234-9022 component after investigating these codes for my car on the internet.

  • The 12mm bolts came out effortlessly, and I was able to remove the heat shield without difficulty.
  • Having applied the provided anti-sieze compound on the sensor, I screwed it on and torqued it to around 35 ft-pounds.
  • I used my obd-ii scanner to clear the codes, and I test drove it to ensure that all of the monitors were working properly.
  • So, despite the fact that my scanner recommended that I replace the oxygen sensor, this component was really effective in eliminating my check engine light!
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Toyota Prius P0138 Trouble Code Finally Solved, The Results Blew My Mind

I’m willing to bet that no Prius owner wants to be inconvenienced by their vehicle. I am also a member of the group. I want to be able to enjoy my Prius without having to worry about anything. When I just purchased a Prius for $600, it had been beaten to a pulp. Because it was unclean and infested with difficulties, it could not be started. I was eager to start driving it as soon as I was able to get it up and running again and clean it. After a short period of time, the P0138 error code was shown.

  • Here’s what I discovered about the issue code and what it required to get it to go away.
  • P0138trouble code is an abbreviation for oxygen sensor high voltage, which is the direct translation.
  • I know from my own personal experience that I have regarded a high voltage as a short circuit.
  • It’s hardly a huge deal, is it?
  • When it doesn’t work, that is.
  • You could feel apprehensive or stressed about it, and you might even have a brief meltdown.
  • That’s exactly what I did in this case.

Technicians who are familiar with the operation of these onboard sensors will perform a new set of tests on the system.

All of the data I was able to get with my factory scan tool indicated that everything was in functioning order.

I was perplexed as to why the light was on if everything was functioning properly.

One of the finest brains of this age to whom I have had the opportunity of reaching out is a Canadian friend of mine, who will remain anonymous for the time being in order to preserve his or her identity from disclosure.

As I began to converse with him, as well as with another buddy, It dawned to me and became evident to me that even while the scan tool may be indicating normal sensor performance, it is possible that the Toyota sensors are defective as well.

Essentially, this is what everything comes down to.

Prius, Yaris, and Rav4 models include an electronic control unit (ECU) that looks at the upstream or principal Air/Fuel ratio sensor and determines what the engine should do based on that data.

So that sensor should cause the check engine light to illuminate, shouldn’t it?

The information is then received from the rear oxygen sensor, which is responsible for verifying the effectiveness of the catalytic converter.

This is not correct.


The Message of the Story The conclusion of this story is that you should never shoot the messenger.

The primary sensor serves as the foundation for all of the fuel trim calculations performed by the ECU.

From that perspective, I believe it makes sense to have a sensor sound the alarm on the other sensor when it fails, allowing you to pinpoint the source of the problem.

Please accept my thanks for taking the time to read this and find the material valuable.

Watch the video presentation of the Toyota RAV4 Plug-in Hybrid Prime for 2021 and click here to subscribe to the Torque News YouTube channel for daily automotive news analysis and commentary.

He graduated with honors from Weber State University with a Bachelor of Science in Automotive Service Technology.

Peter is also a professor of Automotive Technology at Columbia Basin College in Portland, Oregon. Peter may be reached through his LinkedIn profile, and you can follow him on Twitter at @The hybrid guy. His Facebook page may be found at Auto Consulting from a Certified Professional

r/Cartalk – 2010 Toyota Rav4 P0136 & P0138 Replaced w/ Autozone & OEM O2 sensor and still throwing codes!

I’ve discovered the internet! Greetings to one and everyone. I have a CEL with the numbers P1036 and P1038 on it. Instead of doing the difficult route, I just replaced the after CAT O2 sensor with an Autozone one and then reset all of the codes. Within 100 kilometers, CELcodes were once again visible. I purchased a Toyota brand O2 and changed it, which removed the codes. Once again, the codes were returned in a short period of time. What should I be searching for, or what else might it be, before I go back down into the mine?

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I once had to unplug the battery for half an hour to clear an ABS error code from my vehicle’s computer (that was wrong).

However, that is a thoughtlevel 1 situation.

So you’d want to chat about your automobile?

YOUR CAR, your particular automobile that you own, the one that you love/hate/loathe/adore/dislike.

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