It is on the very back right corner of the intake manifold, It's
about 3 inches long with a wire pluged into it on the top. Just
screew it out with plires
There is no relay, only a pressure switch that is wired directly
to the instrument cluster with no relay in between. The pressure
switch is located right next to the oil filter on a 4.6 or a 5.4
liter, and it is sticking out of the driver's side of the timing
cover on a 4.2 liter.