Inspect intake system for vacuum leaks after maf sensor. Maybe problem is there and after engine warms up the problem dissapears.
Precise diagnostics sometimes may save tons of time and money in context of engine and electronics. It is a good a idea to bring car to dealer and ask only for diagnostics. They will tell what the problem is and what are estimated costs for fix. Then you can decide if to do repair by yourself or leave it to dealer.
