P0132: How To Check Your O2 Sensor

Seeing a P0132 trouble code in that OBD scanner of yours? This article will discuss everything you need to know about this code. From the meaning, troubleshooting, the repairs that you might need to do, and cost estimates. Here’s everything you need to know:

P0132 Code

Let’s get straight into it. The P0132 code is defined as “Oxygen Sensor Circuit High Voltage (Bank 1, Sensor 1).” This essentially means that the car’s Engine Control Unit (ECU) has detected high voltage outside of the accepted value from one of the car’s oxygen sensors.

Note that this is a generic trouble code, and it means the same regardless of your car’s make and model. So, you don’t need to research what it means in your specific car make since it’s all the same. An easy way to tell is by looking at the second digit of the code (the number after the letter).


If it’s a ‘0’ such as in this case, then it’s a generic code. If it’s a ‘1’ or a ‘3’ then it’s a manufacturer-specific code and likely indicates different issues depending on the car’s make and model. The number ‘2’ may also indicate manufacturer-specific codes, but some of them are generic.

In any case, if the second digit is anything other than ‘0’ then it’s a good idea to search what it means in your specific car make. Before we break down the code further, you’ll need to understand what the O2 sensor is and what it does:

O2 Sensors: What Do They Do?

An oxygen sensor or O2 sensor, as the name suggests, is a sensor that detects oxygen levels. Specifically, it detects the oxygen level in the exhaust gases from the engine. The purpose of this sensor is to measure and control the engine’s air-to-fuel ratio.

As you probably know, your car works by combusting fuel and air inside the cylinders. This mixture ideally should be at the Stoichiometric ratio, which is 14.7 parts air to 1 part fuel. This ratio provides the best compromise between performance and fuel efficiency. This is why the O2 sensor is sometimes referred to as the Air-Fuel Ratio (AFR) sensor.

The O2 sensor measures the oxygen level in the exhaust gases and feeds that information into the ECU. If the oxygen is too high, then the ECU will try to reduce the amount of air it takes in and inject more fuel. And vice versa if the oxygen level in the exhaust gas is too low.

The sensor has a sensing element and a heating element. The heater warms up the sensor to around 650 degrees Fahrenheit and then it can start to work. Afterward, the heat from the adjacent catalytic converter is enough to keep the sensor at operating temperature.

The sensing element responds to oxygen levels and sends a voltage to the ECU. This voltage is what lets the ECU knows how much oxygen is present in the exhaust gases. The less oxygen there is, the higher the voltage it will send. Usually up to about 0.98 volts, but this can vary depending on the car.

So, if the voltage is excessively high, this means either the sensor is faulty or the engine is burning too much fuel or not enough air.

O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)

Let’s break down the code further. As mentioned, this code indicates that the ECU is getting a voltage reading from the sensor higher than the accepted value. Most O2 sensors will read as much as 0.98 volts, and if it’s above that, the ECU will think that something is wrong with the sensor.

As for the ‘Bank 1 Sensor 1’ part, know that cars have at least two oxygen sensors. One is the upstream sensor, which is the one that’s located before the catalytic converter. And there’s the downstream sensor that sits after the catalytic converter. The reason why there are two is that its second purpose is to measure the efficiency of the catalytic converter.

‘Sensor 1’ always refers to the upstream sensor. Meanwhile, bank 1 refers to exhaust manifold number 1. In V-configuration engines, such as a V6 or a V8, this is a little easier to find. Since the engine have two cylinder banks (row of cylinders), what you need to do is find cylinder number 1.

The exact location differs depending on make and model, but bank 1 is always where cylinder number 1 is located. For example, Ford V8s usually have cylinder number 1 on the passenger side, which means that side is bank 1. Afterward, follow the exhaust manifold to find the O2 sensor.

Meanwhile, inline-four and inline-six engines only have one bank. But sometimes they have two exhaust manifolds, such as in early 2000s Toyotas. So, you’ll need to locate cylinder number 1 and follow its exhaust manifold to find the O2 sensors. But it’ll probably be easier for you to search for exhaust and O2 sensor schematics online.

To summarize, bank 1 sensor 1 means that it’s the upstream sensor on bank 1 of the exhaust manifold that’s faulty.

P0132 Signs

Note that there are several potential causes, and the sensor itself might not be faulty. We’ll get into the causes after this though, but regardless of the cause, you’ll likely encounter these symptoms:

  1. Rough idle. Your engine’s RPM should sit steadily somewhere between 600 – 800rpm when it’s idling at operating temperature. If the needle jumps around, then it’s idling roughly and the P0132 code can cause this because the ECU might not be able to put in the correct mixture.
  2. Increased fuel consumption. High fuel pressure can trigger the P0132 code, and this means your engine is using more fuel than necessary.
  3. Black smoke from the exhaust. If the issue was caused by high fuel pressure, then the engine will get more fuel than it can burn. Unburnt fuel will result in black smoke from the exhaust.
  4. Stalling engine. This is rare, but it can happen. The air-to-fuel ratio might be thrown off so bad that it can cause the engine to stall while driving.


The symptoms may or may not appear when you have a P0132 code, and it depends on the severity of the issue. But if it does, then you should address it immediately. Not only do these symptoms make driving uncomfortable, but they can also lead to long-term damage.

For example, if the car produces black smoke due to this issue, this can clog the catalytic converter. This shortens the catalytic converter’s lifespan, and it can cost up to $2,500 to replace them. Not exactly pocket change for most people.

P0132 Causes & Troubleshooting

Here are the possible causes for the P0132 code:

  1. Faulty oxygen sensor or wiring.
  2. Faulty Mass Airflow (MAF) sensor. This is the sensor inside the air intake system that measures the amount of air flowing into the intake manifold. It helps the ECU to determine how much air to take into the engine amongst other things.
  3. High fuel pressure can cause the engine to take in more fuel than intended. This causes a rich fuel and air mixture (too much fuel) and leads to a high voltage reading from the O2 sensor.
  4. Faulty ECU that’s throwing false trouble codes. This could be because of damage or the ECU requiring an update, but it’s quite a rare issue.
  5. Bad engine coolant temperature (ECT) sensor. A faulty ECT may tell the ECU that the engine is still cold. This results in the ECU injecting more fuel (because cold engines require more fuel to run) and causes a rich mixture causing a high voltage reading from the O2 sensor.

Now that you know the causes, we can discuss how to troubleshoot the code. Don’t go replacing your O2 sensor just yet, cause it might not be the cause. Here’s what you should do:

1. Scan For Other Trouble Codes

First and foremost you should always scan the OBD system with an OBD scanner and see if there are any other trouble codes. Other trouble codes that indicate a malfunctioning part can help narrow down the cause.

For example, a faulty MAF sensor can trigger a P0101 code. This code can mean either the MAF sensor is faulty, or there’s a vacuum leak in the engine. Although the latter is unlikely to throw the P0132 code.


In any case, if there are other trouble codes that indicate a different problem, then you should address that first. The O2 sensor itself may be fine. Instead, there’s something else causing the sensor to send the high voltage signal. Some codes you should look out for include:

  • P0101 through P0109 which indicates issues with the MAF and Manifold Absolute Pressure sensor.
  • Poo88 through P0092 indicates fuel pressure problems.
  • P0115 through P0119 indicate a faulty engine coolant temperature sensor.

Look out for other codes as well, but those above are likely the ones causing the P0132 in the first place. But if there are no other codes present, here’s what to do next:

2. Visually Inspect The O2 Sensor

Before we start removing things, let’s take a look at the sensor first. Most cars will have the sensor underneath the car, somewhere just before the catalytic converter.

However, some cars do have the upstream sensor in the engine bay. Check your service manual if you have difficulties finding your sensor. And wait for the engine to cool down to avoid injuries. Afterward, check the sensor and see if there’s any physical damage to the sensor or the wiring.

The sensor has a metal housing and it kind of looks like a spark plug. And it’s connected to some wiring that supplies it with power. Check both the housing and the wiring, if there’s any kind of damage, then that’s the cause. If not, it’s time to test the sensor and its connectors.

Certain OBD scanners can perform an O2 sensor test. But we prefer to take it out and bench test it, this way you can test whether the sensor itself is faulty or it’s the wiring harness that’s causing the issue.

3. Test The Electrical Connector

Before we test the sensor itself, let’s test the connector to see if the sensor is getting power. This is less likely to cause the P0132, but it’s good to cover all basis. To do this, you’ll need a multimeter, and here’s how to do it:

  1. Disconnect the sensor’s electrical connector.
  2. Turn on the car’s ignition, but no need to run the engine.
  3. Set the multimeter to the DC 20-volt setting.
  4. Most modern cars will have four wires. The colors are different, but usually, there are two wires of the same color for the heating element. And the other one (or two) is for the sensor itself and the ground wire.
  5. Connect the multimeter to the pins of the sensor and ground wire. You should get a reading of about 1.5 volts.

If the connector seems fine, let’s test the sensor itself:

4. Test The O2 Sensor

You can test the O2 sensor without removing it. But if this isn’t feasible in your car, you’ll need an O2 sensor socket to remove it. Then slide the socket onto the sensor, and use a ratchet to unscrew the sensor. Large auto stores may have them for rent.

Once you gain access to the sensor’s connector, here’s how to test it:

  1. Set the multimeter to the lowest Ohm setting. This tests the sensor’s resistance.
  2. Connect the multimeter’s leads to the pins of the two wires that have the same color. Use an alligator clip test lead if you have difficulties connecting the leads to the pins.
  3. The appropriate reading may differ from one car to another. This can be anywhere from 2 to 7 ohms. But if the multimeter isn’t getting any reading, then it’s bad.

The video above is a complete guide on how to test the sensor and the electrical connector. You don’t need to do the volt test on the sensor though, as we already know that the sensor is getting a high voltage reading and we’re trying to find out the exact cause.

Aside from that, it’s a great video and will help you troubleshoot the problem. If you still can’t find the issue, then it’s time to call a professional. Most auto repair shops will charge around $120 for a diagnosis, provided no major disassembly job is required—and none are usually required in this particular case.

P0132 Repair Costs

The repairs and cost will depend on what’s causing the problem. Here are the repairs and its cost that you may need to face:

  1. O2 sensor replacement usually ranges from $150 to $450
  2. Wiring repairs are between $200 and $300 but it may be more depending on the extent of the damage.
  3. MAF sensor replacement costs $350 on average for most cars.
  4. Fuel pressure regulator replacement costs between $150 and $350 on average. But certain cars with electric regulators may cost up to $500.
  5. Engine coolant temperature sensor replacement costs around $250 on average.

All of the estimates already include the labor cost. And since they’re estimates, it may be more or less depending on your car’s make and model, and local labor rates.

O2 Sensor Repairs

Most of the replacement jobs are doable yourself, but some are more difficult such as replacing the ECT sensor and fuel pressure regulator. Additionally, other repairs may be necessary to solve your problem, but the ones we mentioned are the most common repairs.

Note that we don’t recommend attempting wiring repairs yourself unless you have advanced electrical knowledge and skills. We’ve linked the other jobs to relevant articles, and if you need to replace the O2 sensor, here’s how you can do it yourself:

O2 Sensor Replacement DIY

To do this job you’ll need an O2 sensor socket (make sure you have the correct size for your car), a ratchet, and some anti-seize. The process is relatively easy, and you can save up to $100 on labor costs:

  1. Slide the O2 sensor socket onto the sensor.
  2. Attach your ratchet to the socket, and then unscrew the sensor. You can remove it by hand once it’s loose.
  3. Apply anti-seize to the threads of the new O2 sensor. Use just a little and then rub it around with your finger. DO NOT apply it to the sensor head, you’ll need to buy another sensor if you do this.
  4. Insert the new sensor into the plug.
  5. Tighten it with your socket and ratchet. There’s no torque specification, so just tighten until it’s snug but don’t overtighten it.
  6. Reconnect the electrical connector to the new sensor.
  7. Use an OBD scanner to clear the trouble code, this resets the check engine light.
  8. Turn on the engine and drive around for about 15 minutes. If the check engine light doesn’t return, your car is now running well again.

If you need a visual guide, we recommend watching the video above. The video uses a RAV4 as an example though, and it has the O2 sensor in the engine bay. Many other cars will require you to get underneath to replace them, but the steps are the same.

Make sure that you get the correct size for the socket, the right O2 sensor for your car, and that you don’t apply anti-seize onto the sensor head. You don’t need to disconnect the battery to replace an O2 sensor, but the car should be off and you should wait until the car has cooled down to avoid injuries.

P0132 FAQ

Some common questions about the P0132 code answered:

What Causes P0132 Code

The P0132 code is triggered when the Engine Control Unit (ECU) detects a high voltage reading from the oxygen (O2) sensor. Specifically the upstream sensor in bank 1 of the engine. A high voltage reading means the engine is burning too much fuel, and the maximum is 0.98 volts. If it’s above this, then there’s an issue. The cause can be a faulty sensor, wiring damage, or engine issues that are causing excess fuel to enter.

How Do I Fix Code P0132

To fix the code you’ll need to find the exact cause of the problem first. The repairs that may be necessary include replacing the O2 sensor, the engine coolant temperature sensor, the mass airflow (MAF) sensor, and/or the fuel pressure regulator. Wiring repairs may also be necessary. Use an OBD scanner for other trouble codes that may help to narrow down the cause.

What Does Code P0132 Mean

P0132 means Oxygen Sensor Circuit High Voltage (Bank 1, Sensor 1). This code indicates the ECU is getting a high voltage reading from the upstream oxygen sensor (O2) sensor outside of the accepted value, which is 0.98 volts. This can be caused by a faulty sensor, but it may also indicate the engine is burning too much fuel due to air intake and fuel pressure issues.

What Does O2 Sensor Do

The O2 sensor measures oxygen levels inside the exhaust gas. This indicates the fuel and air mixture the engine is burning. If there’s too much oxygen, then the engine is running lean (too much air, not enough fuel). If oxygen is low, then the engine is running rich (too much fuel, not enough air). The sensor feeds this information to the ECU so it can adjust various settings to achieve a Stoichiometric air-to-fuel ratio (14.7:1), which is what the engine needs.

Can I Drive With P0132 Code

If you don’t experience any symptoms with your cars such as rough idle, poor fuel consumption, and black smoke from the exhaust, then you can still drive the car. But you should still address the problem as soon as possible before it leads to severe damage that can cost you a lot of money.

P0132 Code: Final Thoughts

To summarize, the P0132 code indicates that the upstream O2 sensor in bank 1 of the engine is getting a high voltage reading outside of the accepted value. This suggests the sensor is faulty, but it may be caused by something else.

If the sensor is not faulty and there is no wiring damage, then this means the engine is burning too much fuel. This can be caused by a faulty mass airflow sensor, a bad engine coolant temperature sensor, and/or high fuel pressure.

Using an OBD scanner will help you to narrow down the possibilities and help to diagnose the problem. Always do this before you start replacing anything, as it can save you some money. Hopefully, this article will help you solve your problem. Good luck!

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