1999 Accord stops intermittenly
 

When engine fails do all the panel system lights(Check Engine, Oil, Alt) come on or stay off? If off, the ignition switch assy failure is likely.

Since fault is intermittent, it may be diffcult to observe above. Sometimes switch assy failure can be "induced" by wiggling or slightly twisting ignition key position.

Good news is a new keyswitch assy is simple and relatively inexpensive part (< $50).

It could be an intermittent main fuel relay (MFR), however this will be difficult to determine since engine starts immediately after failure. Symptoms for failed MFR are no relay clicks from under the dash and no fuel pump buzz from fuel tank when keyswitch is turned to On. When these conditions are present, engine will not start (no fuel pressure).

good luck

Thanks for the help! The panel lights DO stay on. I thought it might be a relay problem, so I think I will head in that direction.

engine failure en route
 

I am also looking for cause(s) of engine shutting down (especially when i'm in the fast lane going down the highway -- way disconcerting), and had wondered if the fact I have yet to have the serpentine belt replaced on my 1997 Accord LX 4-cylinder had anything to do with it but from what I gather in the quote below it doesn't. My question: are you saying if the the panel system lights stay on it's a faulty MFR?