GMC Repair: buick park avenue 1999, buick park avenue, mass airflow sensor

Question
it was running fine when I parked it Monday, now it won't start on it's own on Tuesday.  When I give it gas it runs, but dies when I let off.  I replaced the fuel filter, checked the codes with the thing from Auto Zone - NO Codes showing.

What else can I do before taking it in?

Thanks

Answer
Hi,Steve
A yes,had many like this in my career,a number of things can cause this,but,there are some simple fixes that rule out them out,ill try to explain as best as possible.
What it may be is the IAC{idle air control}is getting stuck with carbon,this valve is located on the throttlebody if looking at it its on the left hand side has a 5wire connector and looks like a small can sticking out,has 2 screws that hold it in place,you can remove the screws then the IAC,theres an oring seal make sure you dont loose it,get some carb cleaner like gumout and spray both the IAC and the inside of the bore at the throttlebody,clean out all the carbon,wipe both with a rag and reinstall,also clean the throttlebody good including the blade{butterfly}with the cleaner.
 Then disconnect both battery cables,and short them together,this resets the PCM{powertrain computer}and defaults all the data including the IAC position,then restart the car,now it may stall a few times,just restart it,and it should run normal idle,leave the engine running untill it warms up,after normal eng temp turn the ac on and leave it on for 1min,turn eng off,let sit for 1 min,then restart,it should be fine after that and idle normal.
 Also the park ave uses a MAF{Mass Airflow sensor}this may be located on top of the Throttlebody,1999 split the year so some have it there later year 99 has it located inbetween the air cleaner box and the throttlebody at the air tube,if you have the MAF located on top of the throttlebody,its a small square thin box,has 3 screws,remove those screws and wiggle the MAF out,there is also an oring seal there too,and clean the bottom were it has 2 metal wires with the carb cleaner,and then reinstall,these also caused a start stall problem due to carbon build up.if you need more help drop me a line.Thanks

ED