Where is the fuel filter located on a 1990 Mercury Sable?

You will need to jack up the RR corner of the vehicle to reach it. The fuel filter is fastened with a big clamp to the right side frame rail, close to the fuel tank, just ahead of the RR wheel. Use a small flat screwdriver to remove the two plastic clips from the lines attached to the filter. Be careful, the lines are under pressure, and there will be fuel that will spray out as you unplug the lines from the filter. Use a flat screwdriver to loosen the clamo from the body of the filter and then you can remove and replace the filter. Install the new plastic line clips that are in the box with the filter into the lines and then plug the lines onto the filter until you hear them click in place.