O2 SENSOR THREAD CHASER SOCKET
It seems no matter what, removing oxygen sensors (O2) from your exhaust is always the biggest pain. Over the years of expanding, contracting, and moisture, the sensors become rusted in. Once you actually get them out, the threads are most certainly always gummed up. This handy O2 sensor thread chaser socket is a must have tool in your box. This socket features a 18x1.5 thread pitch and can be driven by a 3/4" socket/wrench, or a 3/8" ratchet.
Tip: Try using a little WD40 or anti sieze on the threads while you chase them to help it turn smoothly.