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Q: P0201 p0300 p0301 p0302 check engine light flashing. Good place to start?

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This came out of the blue car ran fine before.

My car has 45600 miles.
My car has an automatic transmission.

Hello and thanks for your question. There is a misfire detected between cylinder 1 and cylinder 2. The codes P0301 and P0302 are directly related to cylinder 1 and cylinder 2. The code P0300 means that there is a random misfire between cylinder 1 and cylinder 2, as they occur not all the time. The code P0201 means that the misfires are recorded by the fuel system not firing on the cylinders, meaning the fuel injectors on cylinder 1 and cylinder 2 and randomly shutting off. With this said, check the fuel injectors on the engine for cylinders 1 and 2 and see if there is any burned wires, loose connections, water standing around the connections, or any fuel around the base of the injectors. If there is nothing around the injectors, then you can remove one injector harness at a time on the engine and hook up a test light with a paper clip to close off the circuit on the harness. This will light up the test light every time the injector is being fired by the computer. If both harnesses are having a voltage reading, meaning the test light flashes, then the injectors are failing and need replaced. If you are having to replace the injectors, I recommend replacing all the injectors to ensure that they all are in good condition. If you need further assistance with your injectors not working, then seek out a professional, such as one from Your Mechanic, to help you.

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