Replace Chevrolet Oxygen Sensor
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Is your Chevrolet check engine light on, engine idles rough, or have you noticed poor fuel economy? These symptoms are often caused by a faulty oxygen sensor that needs to be replaced.
At a Glance
- Read the codes first: an O2 heater or circuit code points to the sensor; lean or rich codes often don’t.
- Upstream sensors (before the converter) affect fuel control; downstream ones monitor the converter.
- Use an oxygen sensor socket; penetrating oil helps on seized sensors, and a warm exhaust loosens them.
- Use a direct fit sensor where possible; universal ones need correct splicing.
- Clear the codes and drive to let the monitors complete.
- A scanner such as the YOUCANIC UCAN-II Pro shows live O2 sensor voltage and fuel trims, so you can confirm a lazy sensor before buying one on supported models.
Before replacing the oxygen sensor on your Chevrolet, you should read the fault codes first to determine if you have a bad oxygen sensor.
Symptoms
- Check Engine Light is ON
- A decrease in fuel economy
- Engine Hesitation or misfire
- Rough Idling
What you will need
- Chevrolet Oxygen Sensor
- Oxygen Sensor Socket
- Ratchet Wrench
- 10mm socket
A universal oxygen sensor can also be used, but you must do the wiring by following the provided diagram in many cases. Most universal oxygen sensors do not come prewired for your vehicle and are not plug-and-play.
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Procedure
Park the Chevrolet on level ground and set the parking brake.
- Pull the hood release under the dashboard on the driver’s side.
- Disconnect the negative battery terminal. Remove the plastic cover. Loosen the 10mm nut. Remove the negative clamp from the battery.
Locate the oxygen sensor on the exhaust manifold. Downstream sensors Bank 1 Sensor 2 and Bank 2 Sensor 2 can be accessed from under the vehicle. Do not touch the sensor or the heat shield until the engine cools.
Disconnect the O2 sensor. Press the connector and pull it away to unplug the oxygen sensor. Use a flathead screwdriver to press the locking tab on the connector before pulling it.
Place the oxygen sensor socket on the sensor and break it loose. If the sensor cannot be loosened, spray penetrating oil and let it sit for at least 10 minutes. This will make removing the old Chevrolet oxygen sensor easier if it is rusted.
Install the new oxygen sensor. Tighten the new Chevrolet oxygen sensor to the recommended torque. Call your local Chevy dealer if you know the correct torque specs.
- Connect the oxygen sensor wire harness by plugging it in. When using a universal oxygen sensor, you will need to use the diagram with the sensor to find which wires to connect.
- Reconnect the battery negative cable.
This guide applies to vehicles such as Spark, Sonic, Bolt, Volt, Cruze, Malibu, Impala, Camaro, Corvette, City Express, Trax, Equinox, Traverse, Tahoe, Suburban, Colorado, Silverado, Sonic, Blazer, Astro, HHR, Uplander, Avalanche, etc.
All Chevrolet cars have at least two sensors, with 6 and 8-cylinder engines having up to four. After you read the fault codes, you will get a code that points to a bad oxygen sensor, such as Bank 1 Sensor 1. This will allow you to identify which one of the oxygen sensors needs to be replaced.
Check Engine Light Still On
If the check engine light is still on after you replace the Oxygen Sensor, you can use the YOUCANIC UCAN-II Pro to clear the stored codes. This scanner can also read and clear fault codes on every control module of your Chevrolet, if your vehicle is supported.
Frequently Asked Questions
Which codes point to a bad oxygen sensor on a Chevy?
Heater circuit codes such as P0135, P0141, P0155 and P0161, and slow response codes such as P0133, point to the sensor. Lean or rich codes like P0171 and P0172 are usually caused by vacuum leaks or fuel delivery problems instead.
Upstream or downstream: which O2 sensor do I need?
Sensor 1 is upstream, before the catalytic converter. Sensor 2 is downstream, after it. Bank 1 is the side with cylinder 1. The code tells you which one failed.
Will a bad O2 sensor hurt fuel economy?
A failed upstream sensor can make the engine run rich and waste fuel. A downstream sensor mainly monitors the converter and has little effect on mileage.
Check these troubleshooting and repair guides for more help on your Chevy.
Hi,
thanks by the information, i’ve a question. When i lunch the scan , i’ve obtained: System too lean , bank 1. So, i need to change the sensor at front or rear ? i read that the Uplander 2006 have two sensors.
thanks