Check the hose clips for tightness and inspect the trunking for any cracks or splits and as a consequence all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best way to find a leak is to have the engine management and hot and then spray can lighter gas /propane or brake cleaner on the subject of each joint in turn. If the engine rev s happening 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 attain a fast irregularity find if you unplug the meter and direct the engine without it. if the engine condition is the same subsequently chances are the meter or the association to it is faulty. Its as well as worth cleaning the MAF sensor wires, as they can get coated like dirt greater than get older which later offsets the reading. Use some approach cleaner or brake cleaner to vaporizer onto the wires to cut off the dirt upon no account lie alongside the wires bearing in mind everything as they are completely fragile
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you up 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 in the works and is warmed up? oftentimes in engine work many factors may cause the thesame symptom(s)