If you chose to upgrade your coils to the D585 or any other variant and you get a CEL afterwards ( P0354 - P0353 - P0352 - P0351 ), here's how to proceed: 1) Make sure that when you upgraded the coils, you also changed your wires and spark plugs. The OEM wires are too thin to handle the Stronger LS coils and you'll end up having issues. So get thicker wires to compensate for stronger coils. ( link in my video on yt ) 2) A CEL can happen because you have higher charge than normal. Simply reset the NVRAM by pumping the brakes 20x fast untill the oil pressure gauge moves. Then simply cancel the code if it does not go away on itself. This should solve the issue. 3) If this doesn't help, then answer the following questions and you'll get an answer. 1. Does the car start, idle hot without problems? 2. Does the check engine light flash on and off or is it steady? 3. What coils did you have before on the car? Mazda original or copies? What exact coils did you install now? (post link) 4. Does the car drive well, i.e. full power and not hesitation etc? 5. Did you change everything together, Coils wires and plugs? 6. Has your car been imported from Japan?