2003 Honda Accord 2003 Honda Accord Low Idle / Stall

My Accord will occasionally begin to idle low, 400-500 rpm, and has now stalled while stopped at a light 3 times. After the stall the engine will start, but will not idle, and I have to keep pushing the accelerator to prevent it from stalling again. This lasts until I get it up to speed for a while, then seems to be ok again.
I had the local dealer look at it each time. The second time they replaced the EGR valve, but that didnt help. They are now telling me it is the computer.
The check engine light never came on until the third time, and they told me it reported a low idle error ( I dont know the codes )
What else can I make sure they have checked before jumping into replacing the computer? What are the other more likely causes? I have seen many times that a computer failure is very rare.