Greetings! Three things come to mind. All three are very important!
U could have a bad mass air flow sensor. This is very common and can cause you vehicle to loose power along with many other drivabilty issues if the sensor is bad. The Mass Air Flow (MAF) sensor uses a hot wire sensing element to measure the amount of air entering the engine. The MAF sensor then outputs an analog voltage signal to the PCM proportional to the intake air mass. The PCM calculates the required fuel injector pulse width in order to provide the desired air/fuel ratio. If the sensor is bad than this air/fuel ratio will be off. This input can also be used in determining transmission Electronic Pressure Control (EPC) , shift and torque converter clutch scheduling.Some MAF sensors have Integrated Bypass Technology (IBT) with an integrated Intake Air Temperature (IAT) sensor. The MAF sensor is located between the air cleaner and the throttle body or inside the air cleaner assembly.
U also could have a lazy or bad oxygen sensor. The heated oxygen sensor is very important to control not only the cars emissions but it also helps the vehicles performance! If it is not working properly it can result in a number of problems like rough running stalling hesitating bucking and jerking. But more common than that if it is lazy, the cars gas miledge can drop considerably, and sometimes not even set a check engine light on the dash! The fuel control Heated Oxygen Sensor (HO2S 1) is mounted in the exhaust manifold where it can monitor the oxygen content of the exhaust gas stream. The oxygen present in the exhaust gas reacts with the sensor to produce a voltage output. This voltage should constantly fluctuate from approximately 100 mV (high oxygen content - lean mixture) to 900 mV (low oxygen content - rich mixture). The heated oxygen sensor voltage can be monitored with a scan tool. By monitoring the voltage output of the oxygen sensor, the PCM calculates what fuel mixture command to give to the injectors.
And last but not least, sounds like u could have bad tune up parts. They usually go bad under a load like under acceleration. But also can go bad at any time. It is very important to have your engine equipt with good tune up parts. If your vehicle is misfiring because of tune up parts than than can cause premature catalytic converter failure. Very common! Good luck!