There are 2 or 3 coil packs that fire the spark plugs, Find the spark plug wire and follow it back to the coil packs, under the coil packs there is a flat piece of metal that has a couple plug in cables going to it, one of those go to the ignition system and one goes to the crank sensor, you will have to follow it but on this car usually it is underneath mounted by the transfer case.
Both correct answers the rear of the engine under the coils is the 2.2 and the front of the engine on the 2.4
I think it may be behind the balancer pulley on the front of the engine.