Chevrolet Repair: 06 chevy 5.3l idle surge, multiple codes, mass airflow sensor, vacuum leaks

Question
I have an 06 chevrolet pickup, 5.3L automatic.  It has just over 200k miles and for the last few months has been idling with a lope or surge.  The first code I pulled was listing Mass airflow and an o2 sensor.  I replaced the Mass airflow with a new one and nothing changed.  The next codes I pulled says mass airflow, O2 sensor both banks, lean mixture, and a couple more.  I have been told by a couple of people that vacuum leaks can cause this, but I have been unable to locate any vacuum problems.  A local mechanic told me that intake manifold leaks are common with this series of vehicles.  What do you think it could be?  If I disconnect the Mass airflow sensor, it idles high, but the surge is gone.  Please help.

Answer
HI TODD, HAVE YOU TRIED OPENING UP THE THROTTLE WHEN THE ENG IS OFF AND LOOK BEHIND IT FOR A BUILD UP OF CARBON..THIS IS FAIRLY COMMON WITH THIS KIND OF MIL. IF THERE IS, GET SOME CLEANER AND [SOFT BRUSH] OR USE YOUR FINGER TO CLEAN ALL OF THIS OFF AND SEE HOW IT RUNS THEN. THE FACT THAT BOTH O2 SENSORS ARE SHOWING A LEAN MIXTURE THIS COULD CAUSE THIS,ALSO YOUR MECHANIC IS CORRECT ABOUT VACUUM LEAKS. TO CK GET SOME CARBURETOR CLEANER  AND SPRAY ALL AROUND THE INTAKE AREA AND THROTTLE BODY WHILE IT IS RUNNING IF THE ENG SPEEDS UP OR IDLES BETTER YOU GOT A LEAK WHERE YOU ARE SPRAYING..I HOPE THIS HELPS YOU AND IF NOT GET BACK TO ME,GOOD LUCK..TOM