A couple weeks ago my XC90 started idling rough and surging up and down with no fault lights. I took it in for repair and it had a (120D) "air mass meter too low" fault and they did a smoke test for vacuum leaks. They found the charge air hose leaking and replaced it. It seemed fine when I left and the mechanic said to keep and eye out for any fault lights and in the notes on the receipt it says the "MAF may still need to be replaced." The next day it started doing the same thing again. I called the mechanic back and he said to bring it back in and they would re-smoke it to be sure and then replace the MAF. I pulled the MAF out and cleaned it with air flow sensor cleaner and it made no difference.

They want $375 to replace it at the shop but I can buy one on Amazon for $90 and do it myself. Any ideas of anything else to try before replacing the sensor? Thank you.