Service engine soon blinks going down a hill at 55 plus. Does not when going slower or when it is cold.
The blinking Service Engine Soon light is warning you that the engine is misfiring and damaging the catalytic converter!! The first course of action is a tune up. Replace the spark plugs and spark plug wires. If you've already done that test the coil packs. If one is failing replace all 3. HTH. -Jim
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