What size socket is the oxygen sensor on a 2018 Toyota Camry?
The oxygen sensors on a 2018 Toyota Camry typically require a 22 mm (7/8 inch) socket, using a dedicated O2 sensor socket with a cutout to clear the wiring.
Understanding the sensor and its size
In Camry models from 2018, both the upstream (sensor 1) and downstream (sensor 2) oxygen sensors share the same hex size on the sensor body. This hex is designed for engagement with a standard socket, though many technicians prefer a purpose-built O2 sensor socket to protect the wiring and avoid damage during removal or installation.
Are there exceptions?
Some aftermarket or specialty sensors might have slightly different fittings, but for stock Toyota sensors in the 2018 Camry lineup, 22 mm (7/8 inch) is the widely used size.
Tools and preparation
Before attempting removal, gather the following tools and materials.
- 22 mm O2 sensor socket (with cutout for wiring)
- Ratchet and appropriate extension
- Penetrating oil (e.g., WD-40) or similar lubricant
- Gloves and eye protection
- Torque wrench for reinstall torque to specification
Using the proper socket helps prevent rounding the sensor hex and protects the wiring harness during removal or installation.
Removal and installation steps
Proceed with care to avoid damage to the sensor or exhaust system.
- Ensure the engine is cool and disconnect the negative battery terminal if necessary.
- Identify the sensors: upstream sensor (sensor 1) before the catalytic converter and downstream sensor (sensor 2) after it.
- Apply penetrating oil to the sensor threads and let it sit briefly to loosen corrosion or carbon buildup.
- Disconnect the wiring harness from the sensor if required, then attach the 22 mm O2 sensor socket and turn counterclockwise to loosen.
- Remove the sensor and inspect the threads; clean them and apply anti-seize compound if recommended by the service manual.
- Install the sensor by hand, then torque to the factory specification using a torque wrench (consult the owner’s manual or service documentation for exact values).
- Reconnect the wiring harness, address any diagnostic codes if needed, and start the engine to verify proper operation and absence of leaks.
Always follow the vehicle’s service documentation for torque specs and sensor replacement guidance.
Summary
For a 2018 Toyota Camry, expect a 22 mm (7/8 inch) hex on the oxygen sensors. Use a dedicated O2 sensor socket with a wiring cutout for best results, though a standard 7/8-inch deep socket can be used if a proper socket isn’t available, with extra care to clear the wiring. This size applies to both upstream and downstream sensors in stock configurations.
