On older vehicles rust can form under the flange and in many cases the bore will expand and the sensor head will break off. I had this problem and did the following steps to extract the broken part. I measured the new sensor diameter and found that a 27/64” drill would bore out the hole to slightly larger than the original bore. I then placed a stop collar on the bit to stop it at a depth of 5/32”. This is the distance between the flange and the top of the O-ring groove. I then drilled to this depth. Two things to keep in mind. The drill bit will self-center when it hits metal so perfect centering is not that important. The part may spin when you get to a depth that clears the rust block. It also is not harmful to ream out the bore as long as you have the stop set safely. I then took a hot soldering iron with a 1/8” diameter tip and melted a hole through the plastic at a sharp angle to make a hole for my hook tool then simply pulled the part out using a hook in this hole.
On older vehicles rust can form under the flange and in many cases the bore will expand and the sensor head will break off. I had this problem and did the following steps to extract the broken part. I measured the new sensor diameter and found that a 27/64” drill would bore out the hole to slightly larger than the original bore. I then placed a stop collar on the bit to stop it at a depth of 5/32”. This is the distance between the flange and the top of the O-ring groove. I then drilled to this depth. Two things to keep in mind. The drill bit will self-center when it hits metal so perfect centering is not that important. The part may spin when you get to a depth that clears the rust block. It also is not harmful to ream out the bore as long as you have the stop set safely. I then took a hot soldering iron with a 1/8” diameter tip and melted a hole through the plastic at a sharp angle to make a hole for my hook tool then simply pulled the part out using a hook in this hole.