Why my car hesitates,then shifts hard on the first shit. Sometimes on the second on 2008 Pontiac G6

It will run good for days then start doing this had it checked out nothing can be found.When checked out a lot of codes came it but still is not fixed

by in Brunswick, MO on March 27, 2012
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1 answer 2 comments
ANSWER by , March 28, 2012
are you getting any trans codes? what are your present codes?
COMMENT by , April 03, 2012
I am having the same problem and the only codes that is coming back are saying tune up got a tune up doing the same thing
COMMENT by , April 04, 2012
seek a diag from your mech