Strange noise especially at low rpms...

[C-24]

Is it possible that the MAF is the source of the problem ?

Because these last days (when I was testing the car intensively) the car would start to "cut" or "struggle", let's say it's in neutral and the rpms are switching from 400-900rpms, and today if I would put my foot down (even in neutral) the car wouldn't go more than 1.5k rpms ! So I unplugged the MAF and the car would then perform better. But after 5k rpms there is no power, it takes years to reach 7k rpms in 2nd or 3rd... even in 1st it's far from sky rocketting lol.

The mechanic says that he thinks the MAF is the problem, because when it's connected, the car is cutting, and when you unplug it, the car is running poor after 4-5k rpms because the mixture of air&fuel is not good.

This was the second MAF I bought so now I'm wondering if I shouldn't directly buy a Hitachi MAF ?

Note : The MAF I have was bought about 1 year and a half ago.

[Dippy]

The Hitachi MAF is not a 'plug-in' replacement.