idle is going up and down like crazy

clean teh throttleplate with choke cleaner on both sides as well as the iac hole. after or before doing this spray choke cleaner around intake manifold to check for a vacuum leak, the rpm will change if it does. then check yoru fuel pressure as it could be low pressure or a pressure regulator.

hi some one told me that it could be the map sensor. do you think that it could be the problem?

it could be but an engine scan would prove that out. if you have a vacuum line going to it, then check for the line being soft and sucking together while running or disconnected.