Mysterious Stalling

My 2004 Regal has been occasionally stalling at low speed over the last two months. It will run fine for days and then shut off when I am slowing down. The car runs fine at highway speeds. The dealership and a reputable mechanic have put it on machines to check the computer diagnostics and the fuel pump pressure. They can find nothing so far. Right now I am driving it, waiting for some pattern to manifest itself. The dealer would love to replace the computer but admits that they don’t think that the computer is necessarily the problem. Anyone run into something similar?

Any Check Engine light on? I’d try some spray cleaner in the throttle body and idle air control valve. How did they rule out the idle air control? This would be a lot cheaper than a new computer.

The Check Engine light has never come on. I’ll ask about the idle air control. Thanks.