Chevrolet Repair: 1997 Chevy Astro, rubber gasket, chevy astro

Question
We have a '97 Astro van with the V6. Last night it started sputtering on acceleration and runs rough on idle. It acts like it is choked up. If you rev the engine the exhaust system rattles and the engines misses. It has over a half a tank of gas. Spark plugs are maybe 8 months old. Coil is 4 months old. Where should I start?  

Answer
hmm,try a higher grade gas, then try engine cleaner that you put in engine with gas. if that helps, could be engine just needs tender care.. try checking for shorts in the igntion system, but from there it just gets more expensive. on my cavalier, it did about the same thing and i found out it was the egr valve, to check this find a bell shaped unit on the engine and under neath it should be a rubber gasket hosued in it. you can push this up and down. now with the engine running push this up , the engine should stall. iof it dont that vavle needs repalced. could also be dirty plugs, bad gas, poor air/gas mixture. and a wide range of other things, but start with the cheapest and easiest and work up. hopefull all this helps.