Just my 2 Cents, I am currently having this same problem, I even had my mechianic looked at it and he didn't seem to mind this obvious problem on the Air Cleaner Intake Hose or ACIH (Picture Attached), The inside was full of grease, dirt and other stuff that went into the Main Throttle Idle Actuator (MTIA) and clogged the holes in it with the same black grease and dirt...sight.
I'll buy the new ACIH have my mechanic clean up all this parts, replace the air filter and I'll post back after all this is done. And maybe get a new mechanic afterwards.
Hope it helps!
PD
I was ready with my soap and water just to check for punctures or leeks and found this!