I have a 1996 dodge avenger, with bout 91k miles on it, got my tranny replaced about a year ago, and have had this problem for a few months now and it is progressively getting worse. when I start my car everything seems fine at first. after driving for a while, I start to notice that at low rpms mainly between 500 and 2500 rpms, my engine seems to "bog" while accelerating, dropping the rpms back and forth almost like it wants to stall, luckily I haven't stalled yet. and after driving for a while also, it will idle at 500 rpms, then ever other second it will fall to 200 rps, then go back up to 500 instantly. Also while accelerating on the highway a few days ago, my check engine light went on, but now it went away. My friend talked to his mechanic and he said it could be something as simple as changing the air filter (not getting enough air because of dirt I guess) or changing the spark plugs. If it was a normal car I would have changed the plugs already, but u know how much of a bitch it is to change them on a v6. My friend also thinks it might be a bad sensor. I appreciate any help u guys can give me.
-Jon