02 stuttering/sputtering/hesitating; never stalling
 

I have a 02 neon with 151,000 miles on it. When it is idling, it stutters/shudders- at stop lights, etc. I think it is going to stall but it never does. If you pop the hood, you actually see the engine "jump" or whatever. When I accelerate again, it hesitates some then goes fine. It has run rough (noisy) for years but now it is just is running like crap and I am afraid it in on its last leg and I am going to be getting a bike!

I took it to the shop about 3 months ago and they said spark plugs, and it ran better for about 200 miles. I have now gone about 800 miles with them and it is running worse than before they were replaced. The engine light NOT on and I have checked for codes "just in case" it was burned out given how poorly it is running, but got nothing. If I put in neutral it used stop before replacing the plugs, now it is just better (smaller jumps).

I swear for the last couple of years it gets "cranky" in colder weather. It was in the 50s this morning and I thought I was never going to get to my destination but then this afternoon 80 and ran better but not great.

Idling, stop and go, uphill and under 50 seems to be worse than 70 on the expressway- which I can't use to get anywhere I actually need to drive to. Ideas?