I have a VERY similar issue ongoing (3rd year) with my 2019 Outback 2.5i, w/37K miles. It was in the dealership service department in Aug ’22 for 6 weeks. No error codes being thrown, only thing they could come up with, in consultation with Subaru National technicians, was the NOC sensor needed to be replaced, and they did a “carbon clean-out”. I drove it another 11 months/7k miles, problem started again (Jul ’23). Took it back to dealership, they kept it 2 weeks, told me it needed “carbon clean-out” again, and that I SHOULD only use 100% unleaded going forward, stay away from e-10 ethanol fuel. NOC sensor is fine this time they said.
My symptoms: loss of acceleration from stop, HIGH RPM’s @ that time, stuttering/hesitation. Does that until I reach about 40mph, seems to run fine on highway……..
