Yes you have two knock sensors I believe, both at the back of the engine. Take the black plastic rubbish off the top of your engine and you will see a blue plug and a white plug on the left hand side on a mounting. One is for the crank position(phase) sensor, and the other is the top knock sensor. The other knock sensor is located lower down on the block, but you should be able to see it peering down the back of the engine with the black plastic binliner rubbish off. They are round and black with a bolt through the centre of them.