( 1 ) PCV valve for your 5.0 liter / 302 cubic inch V8
The Owner Guide shows Motorcraft EV-152 and fordparts.com shows Motorcraft
EV-152-D as the part numbers
Look under the vehicle and count them.
The check " gage " light on in your 1997 Mercury Mountaineer indicates that either your engine oil pressure is LOW , your engine temperature is HIGH or your gas tank is AT OR NEAR EMPTY .
According to the 1997 Mercury Mountaineer owners manual : Your 4R70W automatic transmission capacity is ( 13.9 quarts ) * that of couse would be for the transmission , torque converter , lines , transmission cooler , etcetera *
12 city / 17 highway ( according to fuel economy . gov )
( 2 ) There is a fuse panel in the end of the dash on the drivers side ( the plastic fuse panel cover is visible with the drivers door open ) and the Power Distribution Box in the engine compartment on the 1997 to 2001 Mercury Mountaineer
There are two head gaskets in the V 8 1999 mercury mountaineer
According to the 2004 Mercury Mountaineer Owner Guide : ( 22.5 U.S. gallons )
the four door speakers are 6x8 and the sob if you have one is 8"
There are a total of ( 4 oxygen sensors ) according to the engine wiring schematic for the 1997 Mercury Mountaineer in my Haynes repair manual ( 2 oxygen sensors are " upstream " sensors used by the PCM to adjust the air / fuel ratio of the engine ) ( 2 oxygen sensors are " downstream " sensors / catalyst monitors )
Two.
According to the 2007 Mercury Mountaineer Owner Guide : ( there are 5 lug nuts per wheel )
According to the 2007 Mercury Mountaineer Owner Guide : ( the fuel tank capacity is 22.5 U.S. gallons )