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P0300 on the 2015 Subaru WRX

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

Nobody has written a description of this code yet.

Bulletins for this model year that name P0300
11-161-162017-10-27. Service bulletin. This bulletin announces the availability of new reprogramming files for optimizing the ECM to address the following customer concern: ? Rough idle after a warm engine restart. In rare cases, DTC P0300 may also be stored.
11-161-162016-12-27. Service bulletin. "THIS BULLETIN ANNOUNCES THE AVAILABILITY OF NEW REPROGRAMMING FILES FOR OPTIMIZING THE ECM TO ADDRESS THE FOLLOWING CUSTOMER CONCERN: • ROUGH IDLE AFTER A WARM ENGINE RESTART. IN RARE CASES, DTC P0300 MAY ALSO BE STORED."

2 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.