Bosch 18020 Oxygen Sensor - Upstream

Bosch Oxygen Sensor for Mitsubishi Lancer

Bosch Part Number 18020 is a narrow-band heated oxygen sensor built for precise air-fuel-ratio feedback to the ECU. It is a specific-fit replacement for select Mitsubishi Lancer upstream applications, including 2008-2010 Mitsubishi Lancer, upstream and 2017 Mitsubishi Lancer, upstream.

Key Features

• Bosch Engineered Oxygen Sensor line for OE-style replacement performance
• Narrow-band heated sensor for faster closed-loop operation
• Specific fit with threaded mounting and 18 mm thread size
• 4-wire design with square male connector and blade terminals
• Wiring harness included with 22.7 in harness length
• Metal housing with high-temperature-resistant construction for harsh exhaust conditions
• Part number 18020 for easy identification during ordering and service

Product Details

Bosch 18020 uses advanced ceramic sensing elements and optimized heater control to deliver stable signal output as exhaust temperatures change. As part of the Bosch Engineered Oxygen Sensor line, it reflects Bosch’s long OE development history and the transition from early thimble-style sensors to faster-response planar narrowband designs. This sensor is intended for upstream placement on the Mitsubishi Lancer, where accurate oxygen feedback is critical for fuel control, emissions management, and consistent combustion behavior. Bosch 18020 also cross-references 1588A140 for the same application.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Rough idle caused by inaccurate air-fuel feedback
• Increased emissions from delayed or unstable sensor response
• Poor fuel control during closed-loop operation
• Slow sensor switching on upstream exhaust monitoring circuits

Installation Notes and Tips

Verify upstream sensor location, connector shape, wire count, and thread size before installation. This Bosch oxygen sensor uses a threaded 18 mm mounting design with a 22 mm hex size, so proper removal and installation tools are important. Confirm the vehicle is a Mitsubishi Lancer with the listed fitment and note that the 2014 application is for vehicles without California Emission System.

Quality Assurance

Bosch supplies this oxygen sensor as a standard replacement part backed by decades of OE sensor development and aftermarket engineering. The design uses durable materials and heater control strategies intended to maintain consistent signal quality under thermal and vibration load.