[MOTORHEAD]

Where in the exhaust are you putting it ? Should be in the collector and no more than 90 deg from verticle, which is almost impossible on cobras since most have the collector outside the body which means the 02 bung would be 90 or more deg down from top, and aimed toward the center of the car. It will work in any position, but if mounted from 90 to 180 deg from top position the sensor is more likely to accumulate exhaust residue and cause early 02 sensor failure . I have experienced this.