I've got a 2000 Accord EX.
After idling for a while (like sitting in traffic), when I turn the car off to go into a store or something and then come back out, it will start but it dies immediately. The only way to keep it going is to keep my foot on the gas.
It only does it after idling, never after highway driving.
The check engine light was on for a while, and we were told it was the EGR valve (which we replaced a year ago)...but now the check engine light is off and the car is still acting up....any advice?

 

You describe the typical symptoms of a "hard start condition". If you were to read the codes that lit the Check Engine Light, they'd likely be p03xx; aka,"misfire".

First, read the Honda TSB for this issue. Then read this potential solution.

 

Is this heat soak? from a failed fuel pressure regulator?

The EGR port could need to be cleaned.

 

Visit both links I include in my response to the OP, then parse and process the contents.