Car at slow speed starts spitting and sputtering . I have to turn car off and restart it …what could it be ?
2020 Mustang is reported doing 0 to 60 in 3.5 seconds. If you can’t afford that then you need to get yours scanned at a parts store. And post the code numbers here. Then answers will be more accurate
It might also help if you told us what engine you have, what transmission is in the car, the miles on the car, when this started, if the check engine light is on and a little more description of when this “low speed sputter” happens.
And as @tcmichnorth said, the diagnostic codes read out by the auto parts store. In the form of P0123, not just the reason the auto parts guy says.