Help needed with a specific CEL code...

Help needed with a specific CEL code...
Yesterday, while turning on the engine, my 98 Rodeo (89K), had a little difficulty starting; I should have kept the ignition going little longer, my fault... Then, the second try did not go through. Engine started at the 3rd try... 2 miles after taking off, Check Engine Light came on.
I had it read at the shop this evening while having an oil change. The code is 1404. I called the dealer and I was told that it is related to EGR.
Note that the CEL was not on anymore, when I picked up the car. Is this because the problem was intermittent or because it was simply "read"?
Should I take it to dealer with the code 1404, even though the light is off now?
Thanks very much for your help and time in advance!

Here is a link to the CEL codes.
http://www.troublecodes.net/isuzu/iszuobd2.shtml
Looks like a dirty EGR valve, which is easy to clean.
Here is a link for more information.
http://www.automotiveforums.com/vbulletin/showthread.php?t=299343&highlight=p1404