01 Galant Stalling, low idle

It started like a week ago where the idle would drop pretty low and the engine would turn off everytime I'd stop at a light or stop sign. I had my dad check it and we changed the spark plugs, the oil and oil filter, the air filter, and put in a new thermostat and still the same thing. I had a friend from work check it out and said all I had to do was adjust the idle, but wouldn't that waste more gas? I just wanna get my car running smoothly again without getting ripped. Any suggestions on what it could be. I'm all ears.

try a new TPS (throttle position sensor) that solved the exact same problem on my 92 shadow

I'd suggest pulling a code before replacing anything. TPS is probably not cheap. It could be something as simple as a vacuum leak or an intake leak after the MAP/MAS.

I have to agree with pc here. As he quoted in another post, don't just start throwning parts at it just to see if it works.