Volvo: 2000 S40 stalls when in park, mass airflow sensor, vacuum leaks

Question
I have a 2000 S40 with about 80K mi that stalls and idles poorly when I shift it into park.  When I first took it to the shop they thought it was a vaccuum leak, which they supposedly fixed, but the check engine light returned.  The ECM reported a fault with the mass airflow sensor, which the garage also replaced, but it had no affect; the ECM continues to report a problem with the MAS.  Other pertinent things: The ECM was upgraded/replaced before I bought the car.  When connected to a computer while driving, the computer reported periodic idle surges.  My mechanic wants to do invasive tests that will cost over $1,000.00.  Before I let him do that I want to exhaust all other options.  Could it be the Idle Control Vavle?  

Answer
Hello! I would check the breather (PCV) system. There may be a blockage. Also, recheck for vacuum leaks. It is best to let an experienced Volvo technician diagnose the problem for you. It will cost you more to have someone guess at the problem.


Jimmy