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Honda Insight Oxygen Sensor Guide: 2019-2022 Models

Is a check engine light killing your Insight's legendary fuel economy? A bad oxygen sensor could be the culprit.

4 minutes to read 2019-2022 Honda Insight
Difficulty
2/5
Est. Time
1 hrs
DIY Doable?
✅ Yes
Shop Labor
$60-$120
⚠️ Drivable, but... — You can drive, but you will have poor fuel economy and risk damaging your expensive catalytic converter over time.
Key Takeaways
  • A bad oxygen sensor will trigger your check engine light and reduce your Insight's fuel efficiency.
  • The 2019-2022 Insight has at least two sensors (upstream and downstream) that are not interchangeable.
  • Bosch and Walker Products are reliable aftermarket brands that offer a cost-effective alternative to OEM parts.
  • Ignoring a failed O2 sensor can lead to more expensive repairs, including damage to the catalytic converter.
Your Honda Insight has at least two oxygen sensors that work together. The first sensor, called an upstream or air-fuel ratio sensor, is located before the catalytic converter. It measures the amount of unburned oxygen in the exhaust and tells the engine's computer how to adjust the air-fuel mixture for the best performance and efficiency. The second sensor, called the downstream sensor, is located after the catalytic converter. It measures the converter's efficiency by checking how much oxygen is left after the exhaust has been treated. This ensures your hybrid vehicle meets emission standards.

Understanding the Oxygen Sensor in Your Insight

The oxygen sensors (O2 sensors) are critical components in your 2019-2022 Honda Insight's exhaust and emissions system. Their main job is to help the engine run as efficiently as possible while minimizing pollution. The upstream sensor fine-tunes the air-to-fuel ratio, which is key to achieving the high MPG your Insight is known for. The downstream sensor acts as a final check on the system, monitoring the health of your catalytic converter. When one of these sensors fails, it can throw off the whole system.

Symptoms of a Bad Oxygen Sensor

A failing oxygen sensor doesn't always stop the car from running, but it will cause noticeable problems. Pay attention to these common signs:

  • Check Engine Light: This is the most common symptom. A code like P0139 often points directly to a slow-responding downstream oxygen sensor.
  • 🎬 See how to diagnose and fix a P0139 code.
  • Worse Fuel Economy: A bad sensor can cause the engine to use more fuel than necessary, defeating the purpose of driving a hybrid.
  • Rough Idle or Misfires: The engine may run poorly, idle erratically, or hesitate because the air-fuel mixture is incorrect.
  • Rotten Egg Smell: A sulfur-like smell from the exhaust can indicate that the catalytic converter is not working correctly, which can be a result of a bad O2 sensor.

Don't Ignore a Failing Sensor

While you can drive with a bad O2 sensor, it's not recommended for long. Continuing to drive can lead to poor performance, higher fuel costs, and eventually, expensive damage to your catalytic converter.

Choosing the Right Aftermarket Oxygen Sensor

When it's time for a replacement, you have a choice between OEM (Original Equipment Manufacturer) and aftermarket parts. For the Honda Insight, the original sensors are typically made by Denso. Aftermarket brands offer a more affordable alternative without a significant drop in quality.

Bosch: As the inventor of the modern oxygen sensor, Bosch is a top-tier aftermarket choice. Their sensors are known for reliability, consistent performance, and long life, often lasting up to 90,000 miles. They are a trusted brand used by many professional mechanics.

Walker Products: Walker is a well-respected brand that provides quality aftermarket parts that offer great value. Some sources suggest their sensors may be manufactured by Denso, the OEM supplier for Honda. While their expected lifespan of 30,000 to 50,000 miles may be shorter than Bosch's, they provide accurate readings and reliable performance at a budget-friendly price.

Direct-Fit is a Must

Always choose a "direct-fit" or "OEM-style" sensor. These parts come with the correct connector for your Insight, so you won't have to cut or splice any wires. This makes the installation much easier and more reliable.

Known Issues, Recalls, and Service Bulletins

For the 2019-2022 Honda Insight, there are no specific recalls or Technical Service Bulletins (TSBs) for failing oxygen sensors.

However, it's good to be aware of other issues for this vehicle:

  • Fuel Pump Recall: Some 2019-2020 Insight models were recalled for a faulty fuel pump motor that could cause the engine to stall.
  • AEB System Investigation: The National Highway Traffic Safety Administration (NHTSA) has investigated the 2019-2022 Insight for issues with the automatic emergency braking (AEB) system activating unexpectedly.

These issues are unrelated to the oxygen sensor but are important for owners to know.

Cost of Replacing an Oxygen Sensor on a 2019-2022 Honda Insight

Part Type Estimated Cost
New OEM Sensor $135 - $405
New Aftermarket Sensor (Bosch, Walker) $70.37 - $271.68
Shop Labor $60 - $120

Frequently Asked Questions

How many oxygen sensors does the 2019-2022 Honda Insight have?

The 1.5L engine in the Insight has at least two oxygen sensors: one upstream (before the catalytic converter) and one downstream (after the catalytic converter).

What is the difference between an upstream and downstream sensor?

The upstream sensor is also called an air-fuel ratio sensor and is responsible for the primary fuel mixture adjustments. The downstream sensor's main job is to monitor the health and efficiency of the catalytic converter. They are not interchangeable.

Can I replace the oxygen sensor myself?

Yes, for many owners, this is a manageable DIY job. The downstream sensor, in particular, is often accessible from under the car. 🎬 Watch this step-by-step guide to replacing the rear sensor. You will need the correct wrench (a 22mm or a special O2 sensor socket), 🎬 Watch a professional demonstration of a downstream sensor replacement. and you should only work on the exhaust when it is completely cool.

Should I replace both sensors at the same time?

It is not strictly necessary. You only need to replace the sensor that has failed. However, since they are the same age, if one fails, the other may not be far behind. If your budget allows, replacing them in pairs can be a good preventative measure.

2019 - 2021 Honda Insight 02 sensor replacement (rear post cat)
2019 - 2021 Honda Insight 02 sensor replacement (rear post cat)
New O2 sensors in the Insight an NO MORE PULL BAR!
New O2 sensors in the Insight an NO MORE PULL BAR!
How to Fix HONDA P0139 Code: O2 Sensor Circuit Slow Response (Bank 1, Sensor 2)
How to Fix HONDA P0139 Code: O2 Sensor Circuit Slow Response (Bank 1, Sensor 2)
How to Replace an Oxygen Sensor (Downstream)
How to Replace an Oxygen Sensor (Downstream)

Technical Specifications

OEM Part Numbers: 36532-6L2-A01

The downstream sensor is a 4-wire, heated, narrow-band sensor with a 22mm hex size and an M18x1.5 thread size.

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Meet Wrenchy → Updated Apr 19, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Oxygen Sensor for:
  • Honda Insight: 2019202020212022
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