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Q: Code P0171. Do I need to take car to dealership to address this problem.

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I have replaced spark plug wires, fuel filter, mass air flow sensor and it still runs rough.

My car has 165000 miles.
My car has an automatic transmission.

Hey there. It sounds like your throttle body is bad. Check to make sure it’s clean and not sticking. Clean the throttle body if necessary and check for loose connections with the throttle body connectors, too. Since you said that you replaced the wires, make sure you have all of the connections properly seated and in the right place. If you need to have this checked, a qualified professional from YourMechanic inspect the rough running in order to have this properly taken care of.

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