Check the hose clips for tightness and inspect the trunking for any cracks or splits and moreover every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best habit to find a leak is to have the engine running and hot and next vaporizer lighter gas /propane or brake cleaner as regards each joint in turn. If the engine rev s happening you ve found your leak.
Might also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can complete a quick defect find if you unplug the meter and control the engine without it. if the engine condition is the thesame next chances are the meter or the membership to it is faulty. Its afterward worth cleaning the MAF sensor wires, as they can acquire coated with dirt on top of mature which next offsets the reading. Use some approach cleaner or brake cleaner to vaporizer onto the wires to surgically remove the dirt upon no account touch the wires considering everything as they are entirely fragile
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you stirring to date upon every maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms happening and is warmed up? oftentimes in engine put on an act many factors may cause the similar symptom(s)