2001 Forester Check Engine Light on / clock out

I have a 2001 Forester and the Check Engine Light has been coming on for extended periods of time. It is currently ON, and came on shortly after I refueled last. I have heard that sometimes the light will come on if the gas cap is not screwed back on tightly (to the point where it ratchets shut). But I always screw the cap until it clicks, so I don't think this is it. One mechanic ran the code that I got one time, and the code indicated it needed a new catalytic converter. But the code reset and the dealer could see nothing when I had it in their shop. I did hear that EPA guidelines dictate that Subaru must warrant the catalytic converter up to 80K miles or 8 years on the vehicle, and I now have 73K miles. I will definitely watch to see if the code doesn't go off with the next refueling, and try and ensure it's not the C.C. between now and 80K. But the dealer will charge me >$100 just to check the code, if it doesn't end up being the C.C. as the problem. I have also heard horror stories about the dealers replacing O2 sensors and other parts until AFTER the 80K/8-yr is up, then decide it's a C.C. problem! I'm trying to avoid being "taken" on this. BTW, the car is running fine...doesn't seem to be any problems related to the CEL being on.
Also, the clock above the windshield is out and I really miss it. Any easy fix for that? I suppose I could get a cheap portable digital clock to stick on the dash, and WOULD do that before paying >$80 for a new clock.

I have heard that the clock problem is a resistor needs to be resoldered in the electronics on the clock itself. Should be fairly evident. Hope this helps you. Also on cel check your grounds in engine compartment. Good Luck