[kandem]

Wifey came home and said the CEL came on....I checked it and P0340 came on. I did my research using this site and the search option, but I still have a few questions.
I took it for a quick drive last night, just to see if it was stalling and if the CEL was flashing or steady. CEL was steady, car ran pretty good. I didn't notice any hesitation, or stalling. Then the CEL went out. The code is still logged into the PCM, as it still comes up when I do my key turney thing. Does this mean that the PCM did its own diagnostic test....passed....and turned off the light? I know that has happened on my neon before. I am also wondering if i should be worried about my timing belt. I am at 93 xxx kms, and for some reason there is no manual in the car for me to check a maintenance schedule. I can only assume it would be around 150 xxx kms to change the timing belt. I am just getting ready to do a big tune up on it very soon as I am sitting near 100 000kms and I don't know a damn thing what has been done on this car as far as maintenance goes. I would rather not have to do a timing belt replacement already.