2.
Check leakage of vacuum.
When air-fuel mixture is lean due to leakage of vacuum, ECM closes ISCA. Finally MAF decreased by decreasing intake air and engine hesitation could occur.
Engine "ON" and warm up the engine until cooling fan is operated.
Check leakage of vacuum.
Is there any leakage from vacuum hose?
YES
Repair leakage at vacuum hose or replace it.
NO
Vacuum hose is OK.
