Looking to put a K&N filter on the end of the stock pipe, what is the inner diameter of the factory pipe? I will just use a small piece of pvc of the same diameter for a coupler. Also, how does the factory tube come off the intake? Otherwise I will just angle the tube down and drill the hole for the temp sender so the rubber shards fall out right away. Or would it work better to get a little bit longer piece of pvc and install the sensor in the side of that? Then I can switch back to the factory box without having to plug a hole in the side of the pipe.