Bosch 17242 Oxygen Sensor - Upstream

Bosch Wideband O2 Sensor for Mercedes-Benz C230

Bosch 17242 is an Actual OE wideband oxygen sensor built for precise air-fuel ratio monitoring in the 2003-2005 Mercedes-Benz C230, upstream position. It uses a heated, 5-wire design with a specific-fit harness and threaded mounting for direct replacement service.

The Bosch Actual OE Oxygen Sensor line focuses on OE-style fit, accurate signal response, and durable construction for modern engine management systems. Bosch pioneered the wideband A/F sensor design used across current low-emission applications, and this part reflects that OE development with a planar pump-cell architecture, fast light-off, and controlled heater performance.

Key Features

• Fits 2003-2005 Mercedes-Benz C230, upstream
• Bosch part number 17242
• Wide band oxygen sensor for precise air-fuel ratio measurement
• Heated design with 5-wire harness and 6 terminals
• Specific-fit replacement with included wiring harness
• Threaded mounting, 18 mm thread diameter, 22 mm hex size
• Metal housing with oblong male connector

Detailed Description

Bosch 17242 is a standard replacement wideband O2 sensor for the upstream location on the Mercedes-Benz C230 from 2003 through 2005. It measures the air-fuel ratio across the full lambda range, giving the ECU detailed feedback for fuel control under changing load and temperature conditions. The sensor’s heated construction and robust ceramic element help maintain stable operation during cold starts and rapid driving transitions. This part cross-references Mercedes-Benz 0035427318 for the same application.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings from a worn upstream sensor
• Poor fuel economy caused by inaccurate exhaust feedback
• Rough idle or hesitation tied to slow sensor response
• Emissions test failures linked to faulty mixture control

Installation Notes and Tips

Confirm the upstream location and connector style before installation on the Mercedes-Benz C230. The sensor uses a threaded mount with an 18 mm thread size and a 30.7 in wiring harness length, so routing should match the original path to avoid heat damage or strain on the lead. Inspect the exhaust bung threads and connector condition before fitting the new sensor.

Quality Assurance

Bosch supplies OE and aftermarket oxygen sensors based on more than five decades of engine management development. Bosch 17242 is part of the Actual OE Oxygen Sensor line, built to OE-proven specifications for accurate signal control and dependable service.