R1 POWR

ok guys, i need some help here.

i finally got my HKS downpipe & Efini y-pipe on. everything's all bolted up & tightened. now i've just got to get this O2 sensor in, but it doesn't want to thread in. it's the Bosch universal one, but i'm sure it fits because i had put it in before when the downpipe was just sitting around in the living room. i had the downpipe jet-hot coated, and didn't check the O2 sensor fit when i got the DP back. i'm thinking that either the coating is on a little thick in the sensor hole, at least enough to not let it thread in very easy, OR maybe the first threads on the hole are a little screwed up. either way, i'd like to clean it up with a tap, but i don't know the size. i know it's bigger than an M12 and the thread pitch is 1.5 (my tap & die set only goes up to an M12).

if i had to guess, i would say it's an M14 x 1.5. can anybody confirm this for me????

it's sleep time now, but i'll check back in the morning.

thanks.