I bought my Speed Triple used and it came with an Arrow exhaust. It back fired on decel which annoyed me. I found a nice used stock exhaust which I'm in the process of putting on. Things are going well except the sensor that goes in the exhaust won't fit, the thread is much too big. I can't imagine why the size would be different but they are. Is this a common problem when changing exhaust? If I left the sensor out and put in a bolt to close the hole how would it run? Is the sensor just a plug in change? I haven't dug around yet but the wire seems pretty well hidden.