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Well my engine has a rough idle when i have the car in park, and when i'm at a stop light. My engine also tries to stall (volt meter drops and my rpms drop), when i turn my power steering, when my fan to my radiator turns on, when i use the ac, and when i use my electric windows. Would anyone have a idea whats the problem?? the engine probably have around 150k miles on it, and i have replaced the egr valve, MAF sensor, pcv valve, fuel filter, air filter, cleaned the intake, i also replaced the belt tensioner, idle air control valve, and idle air solenoid. My engine is also making a clicking noise from the top of the engine?? would that be from the ignition or inside the engine? one more thing some of the spark plugs had some white on them