Keep your BMW's fuel management dialed in with the Bosch Oxygen Sensor 13231, an upstream (pre-catalytic-converter) sensor that fits a wide range of BMW models — including the 1987-1995 BMW 325I, 1988-1995 BMW 325IS, 1988-1991 BMW 325IX, 1988-1994 BMW 750IL, 1992-1995 BMW 318I and 1995 BMW M3. See the Buyer's Guide tab for the full list of covered applications.
Mounted ahead of the catalytic converter, this upstream oxygen sensor measures the oxygen content in the exhaust stream and sends a voltage signal to the engine control module, which uses it to trim the air-fuel ratio toward the target. If a worn or failed upstream oxygen sensor is the cause of your issue, this replaces it.
- Sensor position: Upstream — installs ahead of the catalytic converter.
- Function: Reports exhaust oxygen content to the ECM to help maintain the correct air-fuel ratio.
- Direct-fit application: A replacement for the listed BMW models and years.
Signs an oxygen sensor may need replacing include a check engine light, rough or uneven running, and reduced fuel economy — diagnose the cause before replacing, since these symptoms can have other sources.
Interchange: Manufacturer part number 13231.
