O2 Sensor

Cheap Alternative to BMW Oxygen Sensor

I put a Bosch 3-wire O2 sensor intended for a '90 Mustang 5.0 into the 84 325e. The Bosch part # is 13942 (the original 325e Bosch part # is 13008). Replacing it made the car drive a LOT better, and helped the fuel economy as well. The old one was quite dead.

Basically, all Bosch 3-wire sensors are the same, only the wire length and plug differs, it seems. The BMW-specific sensor was priced at over $200 CDN, the Ford one was about $60. Seemed like a good deal to me. There are "universal" sensors in the 1, 3 or 4 wire variants as well - in my case, the universal 3-wire cost a few bucks more than the Mustang one. All the universal ones are is a sensor with no plug and some barrel connectors in the box.

You will have to splice the new sensor to the old sensor's connector. Cut the new sensor's wires near the plug and cut the old sensor's wires off so that the total spliced-together length would be close to the original. Use crimp-on butt connectors to join the wires - black to black, white to white. You can't solder the wires for some reason. I used some heat shrink tubing to cover the joint, then used a bit of silicone to seal the ends of the heat shrink so that no water will get in.

Thanks to Curt Kiser for the sensor info!

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