This could be an airleak after the airflow meter, any expose dragged in here isn t seen by the ECU and hence not compensated for and can thin the engine out and can also permit the engine to rev stirring bearing in mind not desired causing scratchy running. As its a mechanical deformity it tends not to point of view upon the defect light and you can sometimes listen a hissing noise as soon as the engine running.
Might as well as 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 govern the engine without it. if the engine condition is the thesame then chances are the meter or the link to it is faulty. Its with worth cleaning the MAF sensor wires, as they can get coated next dirt greater than times which later offsets the reading. Use some right of entry cleaner or brake cleaner to spray onto the wires to cut off the dirt upon no account lie alongside the wires subsequently all as they are unquestionably fragile
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you going on to date on all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms taking place and is warmed up? oftentimes in engine put on an act many factors may cause the same symptom(s)