Check the hose clips for tightness and inspect the trunking for any cracks or splits and as a consequence all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best artifice to locate a leak is to have the engine running and warm and after that spray can lighter gas /propane or brake cleaner roughly speaking each joint in turn. If the engine rev s occurring you ve found your leak.
Might in addition to be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can get a fast fault find if you unplug the meter and manage the engine without it. if the engine condition is the similar then chances are the meter or the connection to it is faulty. Its then worth cleaning the MAF sensor wires, as they can acquire coated when dirt over era which next offsets the reading. Use some right to use cleaner or brake cleaner to spray onto the wires to separate the dirt upon no account be next to the wires once anything as they are no question fragile
I'm reviewing your ask now, and will broadcast encourage following your answer ASAP. Rgds Greg. What irregularity codes reach you have. Does the engine direct as soon as the MAF disconnected. past the loud hissing unquestionable this could be your problem. This could be a large vacuum leak ,with the MAF partnered it is abandoned measuring the expose that is getting taking into account the MAF, in view of that if the intake manifold is sucking in air the let breathe to fuel ratio will be categorically out and cause the engine to stal