Re: 156 losing power when driving and spit and sputtering
I would check all the simple (non-electronic) things first.
The condition of the spark plugs may be bad. Also the coil (I haven't had a look, but I believe these cars have separate coil packs on each spark plug, but maybe someone else can confirm this). You could also check the ground connections and the battery and alternator voltage.
Do you know if the problem is just one of the cylinders not firing? Or is the problem coming from all cylinders? If you know this it will help you track down the problem.