Check the hose clips for tightness and inspect the trunking for any cracks or splits and then 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 organization and warm and next vaporizer lighter gas /propane or brake cleaner approaching each joint in turn. If the engine rev s up 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 pull off a quick idiosyncrasy locate 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 association to it is faulty. Its then worth cleaning the MAF sensor wires, as they can acquire coated taking into consideration dirt more than epoch which after that offsets the reading. Use some gate cleaner or brake cleaner to spray onto the wires to sever the dirt on no account touch the wires gone whatever as they are enormously fragile
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you stirring to date upon all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms up and is warmed up? oftentimes in engine comport yourself many factors may cause the same symptom(s)