I need to know if anyone knows wheather or not the oxygen sensor bung in the y pipe is 14mm x 1.25 threads or is it 18mm x 1.25, or 18mm x 1.50. I need to retap the bung on mine because the old o2 sensor broke off inside bung and I had to drill it out. I have not drilled enough material out as to cut into the old threads. That's why I'm trying to find out if one of the sizes above is right so I know just how much to take out.