Where is the knock sensor on a 96 Subaru Legacy Outback?

Answer 1

The knock sensor in the 96 legacy outback is mounted on the right side of the engine block underneath the intake manifold.

I recommend having a socket set (with a 12mm socket), plenty of socket extensions, a magnet, a pair or two of pliers, a leaf, and a long skinny screwdriver to accomplish installation and removal of this item.

First, unscrew the bolt by turning counter-clockwise. Second, use the magnet to retrieve the bolt now that it is unscrewed. If you have a larger magnet you can put the magnet on top of your socket wrench (if it is metal) to retrieve the bolt easily. Next, use the two pairs of pliers to pull the knock sensor up out of it's crevice. For easier access to the connection, loop the sensor around behind a metal bar (if facing the front of the vehicle, this would be towards the cabin and left side of the vehicle). Place the white connecting bracket ontop of the nice large metal block that is towards the cabin and use a pair of pliers or screwdriver straight-edge to push the locking piece out of the bracket so the cables can be disconnected. Remove the sensor and install the new one while the cord is in the same place. Loop the sensor and cable back around to where they should be and use the screwdriver to get the sensor face-up and more-or-less aligned with the hole. Put the leaf over the 12mm socket hole and then insert the bolt into the socket. This should provide for a very snug fit of the bolt allowing you to navigate and manuver the bolt with relative ease. Lower the bolt through the sensor and then wiggle the contraption around until the bolt finds the indent of the hole it belongs to. Make certain to hold the wrench straight as you tighten it to reduce the chance of cross-threading. Good luck!

In a little bit more detailed/general description of location: Find the cold air intake for your engine (a big black tube that enters the engine on the side of the vehicle that carries people). Go to the right and follow the top of the engine until you get to the starter cables (the ones that pull when you turn your key in the ignition). The knock sensor is in between these two objects from left to right, and is just towards the cabin of a big metal swoopy object known as the intake manifold. Deep down in this crevice (you probably need about 9 inches of extension on socket wrench with a 12mm socket) there is a solitary bolt that holds in the knock sensor. The sensor itself should be black on the top and have a single cable protruding from it with a white connector on the end that attaches to a grey connector.

If you are mechanically inclined as well as patient, installation and removal is not too difficult. Stand on the side of the vehicle to increase visibilty as well as body leverage for working. I don't know what the torque spec is on the knock sensor, but I know that it is pretty sensitive to how tight it needs to be and overtightening will break it pretty easy. Also, make certain not to cross-thread this when reinstalling as it is threaded into the engine block you'd be in a world of hurt if you messed up. A final word of wisdom is that the sensor and many of the surrounding parts get very hot during operation of the vehicle and retain their heat for a fair period of time - just be careful of this!