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Is upstream and downstream O2 sensors the same?

Is upstream and downstream O2 sensors the same?

The upstream oxygen sensor is situated before the catalytic converter whereas the downstream oxygen sensor is located after the catalytic converter. The upstream sensor monitors the level of pollutants in the engine’s exhaust and sends this information to the ECU that continuously adjusts the air-fuel ratio.

Are downstream O2 sensors interchangeable?

A: Each vehicle is different in the amount of O2 sensors they have. A: The upstream sensor threads into the pipe coming from the engine, closer to the front of the car, and the downstream sensor threads into the catalytic converter, more toward the rear of the vehicle. They are not interchangeable.

Is P0420 upstream or downstream?

A P0420 code indicates a problem with the catalytic converter. The catalytic converter has two oxygen sensors. One oxygen sensor is positioned in front (upstream) of the catalytic converter and the other O2 sensor is positioned at the rear (downstream).

What should rear O2 sensor read?

An O2 sensor will cycle between 0.10 to 0.90 or almost 1 volt. An O2 sensor has to reach the 0.8x Volts amplitude mark while at full operation. An O2 sensor also has to reach the 0.1x Volts amplitude mark while at full operation. (Full operation means the engine is fully warmed up, O2 sensor above the 600 deg.

What are the symptoms of a bad downstream oxygen sensor?

What are the symptoms of a bad downstream oxygen sensor?

  • A Glowing Check Engine Light. The bright orange Check Engine light in your dashboard will usually glow if you have a bad oxygen sensor.
  • Bad Gas Mileage.
  • An Engine That Sounds Rough.
  • An Emissions Test Failure.
  • An Older Vehicle.

What happens if the oxygen sensor goes bad on a Subaru Forester?

When an O2 (oxygen) sensor go bad, it’ll cause your Subaru Forester ‘s engine to run less efficiently. Your Forester can exhibit symptoms when the Oxygen sensor has gone bad.

Where is the O2 sensor on a catalytic converter?

Bank 1 Sensor 1 = O2 sensor located before the catalytic converter, on the side with Cylinder #1. Bank 1 Sensor 2 = O2 sensor located after catalytic converter, on the side with Cylinder #1. Bank 2 Sensor 1 = O2 sensor located before the catalytic converter, on the side with Cylinder #2.

Is the cel light still on after replacing the O2 sensor?

The CEL light has not reappeared after the replace. Thanks a lot for all the pics and the detailed explanation. One thing to note for any other first time O2 replacers, do not attempt to remove the O2 sensor without the O2 socket and a 3/8″ drive breaker bar.

Which is the first sensor on the engine?

Bank & Sensor Conclusion Bank 1 Sensor 1 is the first sensor closest to the engine. On Bank 1 means it is at the engine side with cylinders 1, 3, 5, 7, etc. Bank 1 Sensor 2 is the second sensor on the engine’s exhaust pipe, usually behind the catalytic converter.