It only happens at start up. Not when idling after at stop lights. It only happens at slow or idle. Then the car runs fine. I’ve replaced the IAC, the cam position sensor and synchronizer, the crank shaft position sensor, and found several vacuum leaks. The pvc was cracked and I replaced that. The battery was under warranty and it is new now. The alternator was dead and I put one in from junk yard. It seems to be fine. No dim lights or trouble starting, or random dying while driving. I have two codes now. P1336 and P0156....The first one I thought would be resolved with the fixes I made and the second code is new as of today. I think that’s downstream so I don’t think it would cause this issue. I shock the wires running to various things I thought may cause it and no change. It doesn’t do it all the time. I also replaced the fuel filter, and new spark plugs when I did front and back value cover gaskets and while I was chasing vacuum leaks. Any thoughts or help I’d greatly appreciate.