check engen light cames on and then the car starts mis behaving after about 100 km it goes of again

Hello, You will need to have the vehicle scanned for trouble codes. Intermittent problems like this may be hard to pinpoint, but there will be a history of trouble codes stored on the engine control module, and those will describe why the vehicle is acting in this manner. Further, don't let the parts store tell you what part you need. Sometimes they get lucky, but unless they have an ASE patch on their shoulder, they probably don't understand the issue.