The Camry’s oxygen sensor count depends on the engine option: two sensors for the four-cylinder model and four sensors for the V6 model.
Engine options and sensor layouts
In 2009, the Camry offered at least two major engine choices. The sensor arrangement follows the exhaust design for each engine, affecting how many O2 sensors are installed and where they are located.
Four-cylinder 2.4L (2AZ-FE)
With the 2.4-liter inline-four, the exhaust system typically uses two O2 sensors: one upstream (before the catalytic converter) to monitor the air-fuel mixture, and one downstream (after the catalytic converter) to check catalytic efficiency.
- Upstream O2 sensor (pre-cat).
- Downstream O2 sensor (post-cat).
In this configuration, the Camry has two oxygen sensors in total.
V6 3.5L (2GR-FE)
The V6 engine arrangement generally includes two catalytic converters, one for each bank of cylinders, with an O2 sensor on each side both before and after the catalysts. This results in four O2 sensors in total.
- Upstream O2 sensor for Bank 1 (pre-cat).
- Downstream O2 sensor for Bank 1 (post-cat).
- Upstream O2 sensor for Bank 2 (pre-cat).
- Downstream O2 sensor for Bank 2 (post-cat).
In this configuration, the Camry has four oxygen sensors in total.
Summary
For the 2009 Toyota Camry, the number of O2 sensors depends on the engine. The four-cylinder 2.4L variant has two sensors, while the V6 3.5L variant has four sensors. Understanding the sensor count helps with diagnostics, maintenance, and part replacements aligned to the specific engine setup.