As TJ says. When the engine does something wrong the ECU generates a code, this code has a specific meaning. If you have the code you will have a better idea of what is up with your engine. You will have a better idea of what path to diagnose rather than trying a bunch of random things!

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...He said Smooth Bee the skins is fat
I don't beg cause I'm not in begonia
I dress warm so that I won't catch pneumonia
My rhymes are stronger than ammonia
I'm a diamond, you're a cubic zirconia