Check the hose clips for tightness and inspect the trunking for any cracks or splits and as well as every the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best pretentiousness to find a leak is to have the engine organization and hot and later vaporizer lighter gas /propane or brake cleaner on the subject of each joint in turn. If the engine rev s up 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 reach a fast oddity find if you unplug the meter and control the engine without it. if the engine condition is the similar subsequently chances are the meter or the relationship to it is faulty. Its in addition to worth cleaning the MAF sensor wires, as they can get coated subsequent to dirt on top of period which later offsets the reading. Use some gate cleaner or brake cleaner to spray onto the wires to surgically remove the dirt upon no account lie alongside the wires considering whatever as they are certainly fragile
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you occurring 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 going on and is warmed up? oftentimes in engine play many factors may cause the same symptom(s)