On my 96 3.8, the PCV valve is plugged in on the passenger side valve cover near the back. Part of the PCV assembly connects to the air intake hose, goes across and plugs into the drivers side valve cover. It's a 2 piece setup. I thought the 98's were the same. In any case, just replace the line with a piece of rubber hose. It won't look as clean as the original part (plastic) but it gets the job done. If you can get a nice looking sillicone hose, do that. Don't bother trying to get that part from Ford. They'll charge you your paycheck for that dumb piece.