Location of O2 Oxygen Sensor

Are you trying to find the location of the Oxygen O2 sensors in your Mercedes Benz? Well, pictures are worth a thousand words, so here is one.

Look at the picture; it will show where the Oxygen O2 sensors are located. If you are trying to find any of these sensors: Bank 1 Sensor 1, Bank 1 Sensor 2, Bank 2 Sensor 1, Bank 2 Sensor 2, take a look at the picture below.

To clarify a few things.  This is (was) a 320 M112 engine. Remember that this is the typical configuration for most Mercedes-Benz V6 and V8 engines, such as the M113, M119, M272 M273.

Where to buy OEM Oxygen O2 Sensors and save?

If you have the check engine light on, especially for any of the codes below, you will likely need to replace the oxygen sensor. You can get the O2 sensor online at a fraction of the price. Universal sensors work too, but we recommend original equipment sensors. Bosh typically makes the original O2 sensors. We have set up this Amazon search for original Mercedes Benz O2 Bosch sensors.

Where is Bank 1?

Bank 1 is on the side where cylinder 1 is located; that’s for any car. On the Mercedes – Benz V6 and V8 engines Bank 1 refers to the right side of the vehicle, the passenger side, for left-hand drive vehicles.

• Bank 1 Sensor 1 is the upstream (pre-cat) on the passenger side.
• Bank 1 Sensor 2 is the passenger side’s downstream (post cat).

Bank 2 is on the driver’s side. 

• Bank 2 Sensor 1 is upstream (pre-cat) on the driver’s side.
• Bank 2 Sensor 2 is the downstream (post cat) on the driver’s side.

Where is Sensor 1? 

Sensor 1 is the O2 sensor located before (upstream) of the catalytic converter or the pre-catalytic converter.

Where is Sensor 2?

Sensor 2 is the sensor located after (downstream) the catalytic converter or the post-cat.

What scanner can I use to troubleshoot the check engine light?

The YOUCANIC full system diagnostic scanner is a valuable tool for Mercedes-Benz owners who want to troubleshoot problems with their vehicles. This advanced scanner can read and interpret fault codes from the car’s computer system, providing detailed information about any problems with the engine, transmission, brakes, or other critical systems. The scanner can also perform diagnostic tests on various systems, including the ABS, airbag, and steering systems, to help pinpoint the root cause of any issues. With this information, you can make more informed decisions about repairs and maintenance, saving time and money on costly repairs.

In addition to its diagnostic capabilities, the YOUCANIC scanner can help you reset maintenance reminders and service indicators, allowing you to stay on top of your vehicle’s regular maintenance schedule. This is important because regular maintenance is essential for keeping your Mercedes-Benz running smoothly and preventing significant problems down the line. Using the YOUCANIC scanner, you can ensure that your vehicle is always in top condition, reducing the risk of breakdowns and other issues that could cause inconvenience or costly repairs. Whether you’re a DIY mechanic or a professional technician, the YOUCANIC full system diagnostic scanner is essential for troubleshooting Mercedes-Benz problems and keeping your vehicle in top condition.

 

 

Check engine light codes associated with a bad oxygen sensor. 

Bank 1 Sensor 1 (Upstream) (pre-cat)

• P0130 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
• P0131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
• P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)
• P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
• P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
• P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
• P2080 Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 1)
• P2081 Exhaust Gas Temperature Sensor Circuit Intermittent (Bank 1 Sensor 1)

Bank 1 Sensor 2 (Downstream)  (post cat)

• P2031 Exhaust Gas Temperature Sensor Circuit (Bank 1 Sensor 2)
• P2032 Exhaust Gas Temperature Sensor Circuit Low (Bank 1 Sensor 2)
• P2033 Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 2)
• P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
• P0137 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)
• P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
• P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
• P0140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
• P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

Bank 2 Sensor 1 (Upstream)

• P0150 O2 Sensor Circuit Malfunction (Bank 2 Sensor 1)
• P0151 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)
• P0152 O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
• P0153 O2 Sensor Circuit Slow Response (Bank 2 Sensor 1)
• P0154 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)
• P0155 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Bank 2 Sensor 2 (Downstream)

• P0156 O2 Sensor Circuit Malfunction (Bank 2 Sensor 2)
• P0157 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
• P0158 O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)
• P0159 O2 Sensor Circuit Slow Response (Bank 2 Sensor 2)
• P0160 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)
• P0161 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)

So that is it, how to find where the oxygen sensor is located in your car.

 How to replace a bad oxygen O2 sensor. 

Replacing the downstream / post-cat O2 sensors is easy. It is easy to get under the car to replace them. The upstream ones are a little more tricky, as there is not as much space available for you to work. Here are a few videos that can help you.