Daughter's '04 Optima, replaced the motor about a year ago after a broken timing belt trashed the motor. Has been running great ever since until recently. It will stall with no notice, still has vehicle power and will turn over but not firing. Wait a little while then it runs, till a while later then it stalls again. Shop replaced the crank position sensor and it ran ok for a week, then failed again. Same shop said cam position sensor was bad, replaced that twice since the first one appeared to be bad out of the box. Anyway, now it will run ok till it warms up again, then starts running very rough and then dies (still in the shop). Tech told me that the scanner still calls out the CPS but also something about the injector firing order is way off, causing it to run rough. He is recommending that I take it to a Kia dealer and have then re-flash the ECM and then it will work ok. I am waiting for him to call me back with the current scanner codes before I call the dealer. Timing belt was checked, crank sensor as well, not sure where to go with it, as I think the computer re-flash is a crap shoot. Thanks for any help you can offer, it is much appreciated.