Whistling & chugging 95 mits galant

take it back to whoever installed the coil, it could be defective.

You need a tune up or a new fuel filter or injectors cleaned

clean teh heated wires in the MAF sensor with spray carb cleaner. Good. do not touch.

I had a similiar problem and actually my gear changer in the car was getting hard to move and eventaully stuck.turns out the gear changer was only moving the gears part way and created a wierd sound.Anyway my mechanic found a new gear changing mechanism and installed it .Since then no problems---thank God.

Try a new distributor cap and rotor button,they are known problem areas.If the problem is not in the distributor then you will likely need to replace the catalytic converter,a plugged converter will not let the engine get to full horse power because it can't get rid of the fuel as fast as it is coming into the engine,which is not a problem for the engine at lower rpms but it is a problem when you need the power.

did check engine light come on? if so have codes checked there are many things that could cause this issue, cam sensor, could be one issue

I had a problem like this on my 95 gt 2,2 and it was the distributor cap and rotor. I changed fuel filter, fuel lines, etc. thinking it was fuel related, nope, cap and rotor and 10 minutes of labor and shes perfect.

Check engine light?

Could be the alternator bearings (sound) or could simply be air getting in the hoses check all air hoses by tightenning all the clamp screws (which is quite common to loosen over time can cause the car to run like **** and the sound)

Check for vaccum leak, if not check or replace mass air flow sencor.