2.
Check leakage from the intake hose.
If there is leakage between MAFS and throttle body, Intake air is not sufficient. ECM controls small injection by small intake air and therefore poor power/acceleration could be caused.
Engine "ON" and warm up the engine until cooling fan is operated.
Check leakage from the intake hose.
Is there any leakage from intake hose?
YES
Repair leakage at intake hose.
NO
Intake system is OK.
