1989 Oldsmobile Ciera Sputtering and occasional up and down

I have a 1989 Oldsmobile Cutlass Ciera with the 2.5L Iron Duke engine. It sputters when I rev it up just a little and sometimes it idles up and down. The only way I know to stop it idling up and down is to shut the car off then turn it back on, then it'll rev a little high (1400 rpms) then the rpm's back down to normal (800ish rpms).
I was doing some wikipedia research and they recommend that I replace the map sensor, egr valve (doesn't stick, but may have weak springs), and oxygen sensor. I dont have any trouble codes, but these parts are at least 40,000 miles (about 3 years) old. Should I replace them?

By the way, I have replaced just about everything you could imagine except for these 3 parts, and vaccum lines don't leak.