I'll believe it (I never had to work on the 1.5 gens). Kinda like the 3100 on my old '94 Grand Am, to get at the back plugs, easiest thing is to pull the bracket holding the coils and ICM, slide it out of the way and there they are.... Step forward to my '02 Grand Am with a 3400, back side of the motor is more generous on space, no need to move a thing, just change the plugs (same as my wife's 3400 in her '05 Impala).

 

It helps to start a fresh thread. But to respond to your question, at that mileage and symptom, first thought that comes to mind is when was the last time the spark plugs and wires were changed. If you are still on the factory ones, start with getting those changed. I recommend AC Delco or NGK platinums or irridiums for your plugs. If you have BOSCH plugs, get rid of them.

 

Yea man doing anything to the back of a 3100 sucks in a 5th gen. Surprisingly, my 3800 is much easier to work on. But, if you've ever heard of any 5th gen guys having problems with having to cut/beat the firewall to install headers, again that's because of the 1.5 gen problem.