my car has an issue occasionally that when you are at a stop light or idling the car will shut off, It always turns back on. sometimes when going slow it sputters, then you can put it in neutral and give it gas it runs fine again.. This doesnt always happen but alittle annoying and scary at the same time. The check engine is not on, Recently the master air flow sensor was changed because the same thing happened but when driving down the freeway the car would shut off, That is not a problem any more. Any suggestions.