So randomly my car will start wanting to stall at idle and when coming to a stop in neutral, and then eventually(within 20-30 miles) will give me reduced engine performance and will idle at 600 and rise to 1000 then drop to 600, almost like when an old E30 has the idle air controller issue and just keeps rising and falling at idle, and it also sounds like it is misfiring on one cylinder when the reduced engine performance message is displayed. Turning the car off and on again fixes things completely, but this returns eventually. It will stall on cold starts too, is fine when warm, but after a long freeway trip it will barely idle after getting off the freeway. Everything is back to stock at this point. Any ideas?