Lexus ES350 Air/Fuel Ratio Sensor (2012-2019): A Complete Guide
Understanding the critical role of air/fuel sensors for your ES350's engine health and performance.
- Denso is the original equipment manufacturer (OEM) for Lexus, making their aftermarket sensors a top-quality, reliable choice.
- Your ES350 has two distinct upstream A/F sensors (Bank 1 and Bank 2); you must diagnose the correct one before purchasing.
- A failing sensor will reduce gas mileage and can damage your catalytic converter over time if not replaced.
- The rear sensor (Bank 1) is significantly harder to replace than the front one; professional installation is recommended for that location.
Understanding Air/Fuel Ratio Sensor Failure in Your ES350
When an Air/Fuel (A/F) ratio sensor begins to fail, it can no longer send accurate information to your car's computer. This can cause the engine to run too rich (too much fuel) or too lean (not enough fuel), leading to a variety of noticeable problems. Ignoring a failing sensor can decrease fuel efficiency and potentially lead to more expensive repairs, like damage to the catalytic converters.
Common Symptoms of a Bad A/F Sensor
A failing A/F sensor will almost always trigger the Check Engine Light on your dashboard. Other common symptoms include:
- Poor Fuel Economy: One of the most common signs is a noticeable drop in your gas mileage as the engine compensates for an incorrect air-fuel mixture.
- Rough Idle: Your engine may idle unevenly, sputter, or feel shaky when the car is stopped.
- Reduced Engine Power: The car might feel sluggish, hesitate during acceleration, or lack its usual responsiveness.
- Engine Pinging: A metallic rattling or pinging sound during acceleration can occur from an improper combustion cycle caused by the bad sensor.
Bank 1 vs. Bank 2: Ordering the Correct Part is Crucial
Your ES350's V6 engine has two A/F sensors, and they are specific to their location. Bank 1 (B1S1) is the rear sensor, located near the firewall, and is notoriously difficult to access. 🎬 Watch this walkthrough for replacing the difficult Bank 1 sensor. Bank 2 (B2S1) is the front sensor, near the radiator, and is much easier to replace. 🎬 See how to fix a Bank 2 sensor lean code. Always confirm the diagnostic trouble code (DTC) to identify which specific sensor has failed before ordering a replacement.
Choosing the Right Aftermarket A/F Sensor
When it comes to electronics on a Lexus, brand choice matters. For the ES350, you have excellent aftermarket options that meet or exceed original quality.
- Denso: Denso is the Original Equipment Manufacturer (OEM) for many Toyota and Lexus parts, including these sensors. Choosing a Denso-branded aftermarket sensor is often the same as buying the part from a Lexus dealer, but at a lower cost. They are manufactured to the strictest OE standards for a perfect fit and performance.
- NGK (NTK): NGK, through its sensor division NTK, is another top-tier OEM supplier for many automakers and a highly respected brand. Like Denso, NTK sensors are known for their quality, reliability, and durability, making them an excellent choice for your Lexus.
Pro Tip: Both Denso and NGK/NTK are considered OEM-quality choices for your ES350. You can confidently choose either brand based on price and availability, knowing you are getting a reliable part that will restore your vehicle's performance.
Cost of Replacing an Air/Fuel Ratio Sensor
The cost can vary based on which of the two sensors needs replacement and whether you do the work yourself or hire a professional.
| Item | Estimated Cost |
|---|---|
| New Aftermarket A/F Sensor (Denso, NGK) | $148.10 - $223.10 |
| New OEM Lexus A/F Sensor | $217.00 - $303.00 |
| Shop Labor | $149.00 - $219.00 |
| Total Professional Replacement (Aftermarket Part) | $297.10 - $442.10 |
Note: Labor costs can be higher for the rear (Bank 1) sensor due to difficult access. Prices are estimates and may vary by location and supplier.
Frequently Asked Questions
How many Air/Fuel sensors does my 2012-2019 ES350 have?
Your ES350 has two Air/Fuel ratio sensors (upstream) and two oxygen sensors (downstream), for a total of four sensors in the exhaust system.
What's the difference between an A/F sensor and an O2 sensor?
A/F ratio sensors (upstream, Sensor 1) are more complex and provide a more precise measurement of the air-fuel mixture to the engine computer for immediate adjustments. Oxygen sensors (downstream, Sensor 2) are simpler and primarily monitor the efficiency of the catalytic converter. They are not interchangeable.
Can I replace just one sensor?
Yes. You only need to replace the specific sensor that has failed and triggered the diagnostic code. A diagnostic scan tool can identify the exact sensor location (e.g., Bank 1 Sensor 1).
Is there a recall for the A/F sensor on my Lexus ES350?
Searches of NHTSA data did not find any specific recalls for the air/fuel ratio sensors on the 2012-2019 Lexus ES350. Recalls found were for other issues like fuel pumps or airbag occupant sensors.
How difficult is it to replace an A/F sensor?
The front sensor (Bank 2) is relatively easy to access. However, the rear sensor (Bank 1) is very difficult to reach due to tight space against the firewall and is often best left to a professional mechanic. A special slotted oxygen sensor socket is required 🎬 Watch a guide on how to check and replace sensors. for the job.
Helpful Videos
Technical Specifications
OEM Part Numbers: 89467-0E250 89467-53090 89467-07030 89467-07020 89467-06120 89467-07010
The upstream sensors are wide-band Air/Fuel Ratio sensors, while the downstream sensors are traditional Oxygen sensors. They are not interchangeable. The V6 engine has two banks: Bank 1 is the rear bank (near firewall) and Bank 2 is the front bank (near radiator). Sensor 1 is always upstream (A/F sensor) and Sensor 2 is downstream (O2 sensor).
We Have This Part in Stock
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.
- Lexus ES350:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Understanding Air/Fuel Ratio Sensor Failure in Your ES350
- Common Symptoms of a Bad A/F Sensor
- Bank 1 vs. Bank 2: Ordering the Correct Part is Crucial
- Choosing the Right Aftermarket A/F Sensor
- Cost of Replacing an Air/Fuel Ratio Sensor
- Frequently Asked Questions
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