this is an easy fix. the problem is the iacv. just ask for that part at dealer change it out and the problem is fix.
one
According to the 1997 Mercury Cougar Owner Guide : ( Motorcraft FG-881 fuel filter ) for the 4.6 litre V8 and the 3.8 litre V6
For a Mercury Cougar , 2.5 litre V6 engine : According to the 1999 to 2002 Owner Guides : ( Motorcraft FL-820 engine oil filter )
the transmission has to be spit apart in order to change the trans filter.
near the oil filter
Gasket should be included with new oil filter
On a 2001 Mercury Cougar : The Mass Air Flow Sensor is between the engine air filter and the big engine air intake tube
The filter is actaully located inside of the transmission itself.....you would have to remove the transmission and tear it apart to get to the filter
I pretty sure your looking at 5 with the filter.
According to one of Fords websites : For the 1972 Mercury Cougar , 5.8 liter / 351 cubic inch V8 engine : ( Motorcraft FL-1-A engine oil filter )
Fuel Filter under PASSENGER SIDE between front and rear wheel.
The sound is called moosing. It's usually an indication that either the IAC valve (Idle Air Control) valve or a sensor is going bad.