After soaking the Air Flow sensor on my 2000 RX 300 for two days I thought it would be a relatively easy procedure to remove and replace....wrong! The threads from the old AF Sensor stayed in the manifold. I attempted to chase the threads with a 18mm 1.5 plug chaser bought at my local auto parts store. I was able to get 2-turns before it would not go any further. Can anyone tell me the correct thread pitch for the Air/Flow Sensor. Thanks Sword5