Oxygen Sensor for Mazda CX-7 2.5L 2009-2012 Downstream Post-Cat 4-Wire Heated Aftermarket Replacement
Upgrade your Mazda CX-7 with this downstream Lambda Oxygen Sensor from WEIDA AUTO PARTS. Designed for the 2.5L engines found in 2009–2012 CX-7 models, this 4-wire heated sensor plugs into the exhaust stream after the catalytic converter to provide accurate post-cat oxygen readings. It’s compatible with the OEM part number L556-18-861, ensuring a precise fit and reliable operation. Originating from Mainland China, this sensor brings factory-style performance at a value-driven price, helping your vehicle maintain optimal fuel efficiency and emissions compliance.
This sensor plays a crucial role in the engine management system by monitoring exhaust oxygen levels after the catalytic converter. Accurate downstream readings help the ECU fine-tune the air-fuel ratio, support proper catalyst function, and reduce the likelihood of diagnostic trouble codes. The built-in heater feature ensures quicker sensor warm-up, delivering stable readings even during cold starts for smoother idle and improved driveability. All electronic and mechanical equipment, devices and machines sold by InterCyprus to EU countries are CE certified and carry a two year warranty. At intercyprus.com since 2002 — trusted for quality and reliability.
Language support: English (where available).
Benefits & Tips
- Improves post-cat oxygen sensing to help the ECU maintain optimal fuel economy and lower emissions by delivering accurate downstream readings.
- Heated design enables faster warm-up in cold weather, reducing sensor lag and improving drive-by-wire responsiveness during initial startup.
- Ideal for diagnostic and maintenance cycles—replace a failing downstream sensor to prevent catalyst damage from incorrect air-fuel adjustments and to resolve related fault codes.
Product specifications
- Brand: WEIDA AUTO PARTS
- Application / Fitment: Mazda CX-7 2.5L (CX7 ER) 2009–2012
- OEM No.: L556-18-861
- Sensor Type: 4-wire heated downstream oxygen sensor
- Location: Downstream (after the catalytic converter)
- Origin: Mainland China
- Measuring Range / Capacity: Specified for Mazda CX-7 2.5L 2009–2012
Package includes:
- 1 x Downstream 4-Wire Oxygen Sensor for Mazda CX-7 2.5L (2009–2012)
Warnings / Reminders
- Ensure the engine is cool and the battery is disconnected before installation.
- Verify correct fitment to OEM part L556-18-861 and handle connectors with care to avoid damage.
- After installation, clear any codes and run a diagnostic to confirm proper sensor readings and readiness monitors.
All electronic and mechanical equipment, devices and machines sold by InterCyprus to EU countries are CE certified and carry a two year warranty.
Providing quality and trusted service since 2002 at intercyprus.com.