Sounds like symptoms of BRANT to be honest..Search BRANT issues.. I myself experienced similar symptoms until I had mine looked at by my mechanic. I thought it was the Fuel Pump or something that was causing it until I was shown the exact symptom demonstrated & replicated in front of me, which turned out to be that of the joys of BRANT. The part that failed for me was the fuel cut situation where "ANTI-HIJACK" was engaged erroneously.

A Very well known issues. Best to have a Subaru Specialist or Subaru Investigate, Fix & or remove/replace.

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