my mechanic changed spark plugs, but my car is still missing if u no what I mean, he suggested new spark plug wires, since I've had the car some 75000 miles,
My car has 179000 miles.
My car has an automatic transmission.
Old or faulty spark plug wires can definitely be a cause for the engine to misfire, however there are numerous other reasons that may also cause this to happen. Generally, misfires are caused by either a spark or fuel issue or in cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly. When the misfire results from a fuel related issue, this is commonly related to a lean fuel condition (lack of sufficient fuel supply to the motor). Fuel related misfires can be caused by many different things such as low fuel pressure, faulty or dirty fuel injectors, a faulty O2 sensor, a dirty or failing mass air flow sensor, a faulty or dirty idle air control valve or a vacuum or intake leak. When the fuel supplied to the combustion chamber is insufficient, this results in an ignition (spark) that is igniting a less than balanced load of fuel and air. I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem.
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