Check the hose clips for tightness and inspect the trunking for any cracks or splits and next all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best exaggeration to find a leak is to have the engine processing and warm and subsequently spray can lighter gas /propane or brake cleaner approximately each joint in turn. If the engine rev s happening you ve found your leak.
Might furthermore be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can complete a fast deviation find if you unplug the meter and manage the engine without it. if the engine condition is the thesame after that chances are the meter or the membership to it is faulty. Its along with worth cleaning the MAF sensor wires, as they can get coated past dirt higher than epoch which later offsets the reading. Use some approach cleaner or brake cleaner to vaporizer onto the wires to remove the dirt upon no account touch the wires considering whatever as they are unconditionally fragile
I'm reviewing your ask now, and will read out assist afterward your respond ASAP. Rgds Greg. What irregularity codes realize you have. Does the engine govern in imitation of the MAF disconnected. as soon as the loud hissing strong this could be your problem. This could be a large vacuum leak ,with the MAF connected it is and no-one else measuring the ventilate that is getting once the MAF, therefore if the intake manifold is sucking in let breathe the ventilate to fuel ratio will be no question out and cause the engine to stal