I recently flushed the radiator, replaced plugs with platinum 2 plugs, changed air filter, oil and filter, and pcv valve. I had cil for o2 sensor. So I changed it and solved the problem. Took a 300 mile trip all highway cil came back on , then 2 days later went out and now I am having a stutter in acceleration on the second start and trip out, but no problems when I first start and go to work. If I stop at a store and start back up that's when I have the problem. Plus idle seems to run high in park and low at red lights almost low enough to stall?????

change to ngk plugs, they work better. and try cleaning the throttle body and idle air sensors around it.