my hyundai is stalling intermittingly the tack will drop then go back up on 2004 Hyundai Santa Fe

i can be sitting in traffic or just idle and it will stall itermittingly please can you help me i've taken it to two shops one the dealer the other independant and when they put it on diag. machine found no error codes

Asked by for the 2004 Hyundai Santa Fe
What about the datastream while the engine is running? Keep googling the problem and someone else may have found a solution already. GL