Once I give a full throttle from 2nd gear, I get a hesitation in acceleration between 5,000-6,000rpm. Actually, the RPM shortly goes down in the range @ WOT. If I gently control the gas pedal though, the symptom doesn't bother me. Besides the range I mentioned, my 07 GT3 runs great without any power loss or hesitation.

Is it caused by bad MAF? Any ideas?

 

MAF, could be but it sounds like a fuel delivery issue. Maybe your fuel pump is going but I'm just guessing.

 

What's your rev limiter set at? That will cut fuel delivery when you hit it.

 

check codes first, THEN panic.

 

No codes, no fuel cut
Can GT3's racing gear ratio cause the issue?

 

VarioCam ?