'02 GLS, MIL light is on but no trouble codes. Also, any other cars to swap parts?

[UnspoiledWalnut]

My check engine light has been on for a while, but when I scanned it for errors with my friend's diagnostic thing it didn't return any trouble codes for either the engine or transmission, and when we tried to clear it, it was unsuccessful. I asked on Yahoo Answers, and one guy told me the tool wasn't working right, but I've used it before and it was fine and he's a mechanic for UPS, kinda uses it like every day so I'm pretty sure that it's not malfunctioning.

I was told to touch the battery cables together for a few seconds to clear the ECM out or unplug the airflow sensor or something to create a code but I've never heard of doing either of those (then again, never had an issue). I'm just wondering if that's a good idea, as Yahoo Answers doesn't always have people who know what they're talking about and following their advice generally can cause something to break, which I don't want to do because I throw enough money at my other cars for doing stupid things with them and need one that runs.

And for the second part, are there any other cars that with the same door or mirrors as a 2002 GLS that I could use in place of ones from a Sonata (not a very common car to find in a junkyard apparently, there's a place in Spokane that has a couple of older mid '90s but I think it's changed quite a bit so those won't fit). I broke the casing for the driver's side mirror (hit a deer, somehow it only actually hit the mirror and broke the plastic, there's a big hole in it and I don't like it), and my friend knocked the chrome moulding strip thing off the front passenger door when he tripped and then didn't put it back on right so it fell off somewhere on what I think is a really long back road. I also wouldn't mind getting a new rear bumper cover since it was cracked when I got it, but I don't care so much about that as having holes in my door and mirror.