When I start my car it runs fine after 15 min of running I put it gear and it putts and shut off and sounds like it locking up put it back in park its back to normal and idles perfect.I've put in new exhaust from converter to the tail pipe egr value I think it need 02 sensor. And when shuts down it won't turn over like locked up.wait a few hours it will start and does the same thing all over again