I cranked the Durango up one morning and it made a loud pop and now runs very bad .
My car has 130000 miles.
My car has an automatic transmission.
This can happen for many reasons, however usually a loud pop or backfire is a sign of a lean fuel condition or an ignition timing problem. A lean fuel condition can be caused by a faulty mass air flow sensor or throttle position sensor.
This issue should trigger a Check Engine Light which will register some fault codes in the car’s computer. I would recommend having an expert from YourMechanic come to your home to diagnose any trouble codes using a scan tool which will help to download specific details as to which parts have failed.