I'm assuming its an electric sensor. I would say its either coincidence or a wire is unplugged. Look at the side of your driver side head between cylinders 1 and 3 for something about 1" in diameter threaded into the block and see if theres a wire coming off of it. Make sure the wire is connected to it and make sure the wire isnt damaged, shorting, burnt, etc. Your sensor could have gone out coincidentally when you did everything, but since it pegs of high instead of not moving, I'm guessing a ground? Theres a ground for the instrument cluster that could have come unhooked or not hooked back up, and I would guess it would peg high like a gas gauge would when the ground is missing.