like i say, its the 4 pin one in the front coolant flange on the head

follow the top radiator hose to the head, plastic bit is the flange. sensor is in the top, held in with a clip. wait till engien is stone cold before you swap it, and remove header tank cap and refit to release any residual pressure. it should have an oring on the bottom, so make sure you swap this over from the old sensor, or if you get a new oring make sure you remove the old one if it got stuck in the flange
