This could be an airleak after the airflow meter, any expose dragged in here isn t seen by the ECU and in view of that not compensated for and can thin the engine out and can after that permit the engine to rev occurring subsequent to not desired causing harsh running. As its a mechanical irregularity it tends not to face on the oddity roomy and you can sometimes listen a hissing noise later the engine running.
Might furthermore be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can complete a fast deviation locate if you unplug the meter and rule the engine without it. if the engine condition is the same after that chances are the meter or the link to it is faulty. Its moreover worth cleaning the MAF sensor wires, as they can acquire coated as soon as dirt exceeding time which later offsets the reading. Use some entry cleaner or brake cleaner to vaporizer onto the wires to sever the dirt on no account touch the wires following all as they are very fragile
later I begin the car, the engine surges stirring in the midst of 1200 and 2000 rpm support and forth. I untouched the IAC and the TPS subsequent to no change in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to acclimatize the idle speed screw to subjugate the rpm and it would sustain for a while. Now, the engine is every time surging to the narrowing where I cannot steer it for distress signal of damage to the steer train. Any experienced solution?