My car conumes a lot of fuel and it emits black smoke and draggs while in motion I have to apply more presure for it move and the steaming isn't steady most times it will trip off especially with ac on

Oxygen sensors are a major cause of poor mileage. You should have the system scanned for trouble codes to determine a baseline for diagnosing possible sensor failures. When oxygen sensors fail they can create many symptoms as well cause damage to catalytic converters so have it checked as soon as possible!