Some vehicles may experience a rough idle with the check engine light on and DTC P0015 / P0524 stored in memory. P0015:00 - Exhaust CMP timing over-retarded. P0524:00 - Engine oil pressure too low. This is caused by a drop in engine oil pressure due to a piece of foreign object stuck on the oil pump pressure relief valve or oil control valve (OCV). The temporary entry of the foreign object triggers a check engine light on, but rough idle will not be produced until a later time.
