2001 Saturn SL1 Saturn engine performance problem

Our 2001 Saturn SL1 (38500 miles) has been having some idling and acceleration problems for a while now. I started noticing a very rough idle that would infrequently occur when at a stop or in park. This escalated into some engine 'sputtering' when accelerating. Service light began coming on and then off. I took it in and got it read, came back we needed new Camshift postition sensor, crankhaft postion sensor, and new plugs for good measure.

It ran fine for about a week then it was back to the same problems. I took it back in and now the diagnostics came back with random misfirings. Mechanics believed it was eletrical but couldn't be certain.

Things are progressively getting worse. At around 35-40 mph when accelerating, car wants to jump or sputter. Hard idle still frequent. There is definitely a problem when gas tank gets close to 1/4 tank-seems to be more frequent.