The 2005 Accord's oxygen sensor count varies by engine: the 2.4-liter inline-four uses two O2 sensors, while the 3.0-liter V6 uses four sensors (two per bank). The sections below explain the sensor layouts for each engine option.
Engine options and sensor layouts
Honda offered two gasoline powertrains in 2005: a 2.4L inline-four and a 3.0L V6. Each engine uses oxygen sensors to monitor exhaust, but the number and placement differ by configuration.
2.4L inline-four engine
The four-cylinder variant has two O2 sensors in total: one upstream sensor before the catalytic converter and one downstream sensor after it. This is the standard two-sensor setup for the 4-cylinder Accord of that era.
- Upstream O2 sensor (Bank 1, before the catalytic converter)
- Downstream O2 sensor (Bank 1, after the catalytic converter)
In summary, the 2.4L engine uses two oxygen sensors overall.
3.0L V6 engine
The 3.0L V6 uses two exhaust banks. Each bank has an upstream and a downstream O2 sensor, giving a total of four sensors.
- Bank 1 upstream O2 sensor
- Bank 1 downstream O2 sensor
- Bank 2 upstream O2 sensor
- Bank 2 downstream O2 sensor
In summary, the 3.0L V6 uses four oxygen sensors in total.
Summary
For the 2005 Honda Accord, sensor count depends on the engine: 2 sensors for the 2.4L inline-four, and 4 sensors for the 3.0L V6. If you’re diagnosing or replacing sensors, identify your engine variant to ensure you source the correct parts and sockets for the upstream and downstream sensors on each bank.