1995 Dodge Neon ignitoin coil

I used an aftermarket one this last time but the time before I used one from the dealer and it lasted 13months which was a month longer than the warranty lasted also this is what else I recently posted if it might be related.

OK so my car hesitates when you try to accelerate. It also does it at freeway speeds but you can only notice it if you have the ac on. It is the worst in reverse, if you have the ac on in reverse it almost dies. So my bf works at a shop, first they said its a vacuum leak so he replaced some old crusty vacuum lines, that didn't help so he changed the spark plugs and that fixed it for about a week but now its back, worse than before. I don't like to pay for things that don't actually fix the problem so I need some more input. Any ideas? Oh and he said the spark plugs were white like it's running lean or something. Thanks