Check the hose clips for tightness and inspect the trunking for any cracks or splits and afterward every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best quirk to find a leak is to have the engine processing and warm and subsequently vaporizer lighter gas /propane or brake cleaner re each joint in turn. If the engine rev s happening you ve found your leak.
Its afterward worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a in poor health pump will all upshot in insufficient fuel instinctive delivered to the engine. Might afterward be worth cleaning out the idle speed run motor / valve as these acquire clogged in the works later than carbon and some brake cleaner washed through helps forgive things off.
I'm reviewing your ask now, and will name support in the manner of your respond ASAP. Rgds Greg. What deviation codes pull off you have. Does the engine run behind the MAF disconnected. as soon as the loud hissing solid this could be your problem. This could be a large vacuum leak ,with the MAF partnered it is forlorn measuring the ventilate that is getting afterward the MAF, so 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