How to know the mass air flow part is broken

Question

the rpm dont up more than 1200

Answer 1

To test the MAF sensor you measure its signal output, the output voltage at idle is about 0.5 volts , at 3000 RPM its signal voltage is about 3000 RPM, A faulty MAF will set a fuel trim rich and some times a fuel trim lean code at the same time. Even with a faulty MAF the RPM should be able to go over 1200 RPMs,