When I started the vehicle it ran it started rough and ran rough despite running perfectly the night before. The CEL came on solid, then after a while the VSA light came on solid and the CEL changed to blinking. Once the VSA light came on the VSA switch no longer worked to turn on or off the system. A reset/restart resets the sequence. The VSA switch works but only until the VSA light comes on. I pulled the code and got P0303 for cylinder 3 misfire. What is the most likely failure point for a sudden failure? I am leaning toward replacing the coil, but am not sure if that is the most likely fault. I noticed that when I turned the key on the electronic sound I hear each morning (perhaps fuel pump?) seems to run a bit longer than usual. Do you recommend an OEM replacement coil or other? Overall car is in great condition.
My car has 66580 miles.
My car has an automatic transmission.
Hi there. An ignition coil would definitely be a very good guess. However, that is exactly what it would be: a guess. When a misfire code is stored, the ECM reads a slow down on that particular cylinder. Why this has happened, the computer does not know; it only knows that the cylinder moved slower. When the check engine light flashes this is a warning to the driver that possible catalytic converter damage may occur from the misfire; continued use can result in an expensive part replacement. The misfire you have can be caused by many different things and truly needs to have an inspection performed. Without viewing scan tool data and performing the appropriate testing procedures, we are pretty much throwing darts at a dartboard and we may get lucky enough to hit the target. I strongly suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a check engine light inspection.
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