Throttle Position Sensor?

My 96 Impreza has been giving me problems. A few months back, it started to pop and putter in early first, second, and third gears. We thought it might have to do with the spark plugs, so we replaced them and replaced the wiring as well. That fixed the puttering until a few days ago. It makes a backfiring sound when I accelerate, and it's really sluggish. What does it sound like the problem is??:???:

 

I'd guess either MAF or o2 sensor. Any check engine lights?

 

knock sensor, and/or coil

 

Yeah, a bad coil could be it also.

 

No check engine lights.

 

that leads me to think coil...i have one if you wanna try it

 

I'll definitely try it. Would it also make a knocking sound when I turn?

 

no, that would probably be your cv axles

 

Man. My car needs a makeover, I guess! How much do you have the coil for?