My honada civic 2001 runs smothly but when I come to a stop the car starts to shake violently and then the car turns off compelely what might the prob;em be ? Oh and I took it to the shop for a headgasket fix and then after the guy at the shop said it was still shaking and didn't know why it was doing that he sujested to me that something was clogging it up to make this shake ?

If the engine overheated and you blew the head gasket, the problem is likely related to that. There may have been valve and/or camshaft damage. Remove all the spark plugs and check each cylinder's compression.