If there is leakage between MAFS and throttle body, Intake air is not sufficient. PCM controls small injection by small intake air and therefore poor power/acceleration could be caused.
Engine "ON" and allow the engine to warm up to normal operating temperature.
Check leakage from the intake hose.
Is there any leakage from intake hose?
YES
Repair leakage at intake hose.
NO
Intake system is OK.