Check the hose clips for tightness and examine the trunking for any cracks or splits and along with every the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best habit to locate a leak is to have the engine organization and hot and later 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 plus be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can complete a quick aberration find if you unplug the meter and direct the engine without it. if the engine condition is the thesame after that chances are the meter or the link to it is faulty. Its then worth cleaning the MAF sensor wires, as they can acquire coated behind dirt more than times which subsequently offsets the reading. Use some right to use cleaner or brake cleaner to spray can onto the wires to cut off the dirt upon no account be next to the wires gone whatever as they are entirely fragile
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you taking place to date on every maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms stirring and is warmed up? oftentimes in engine pretend many factors may cause the same symptom(s)