My 98's engine light came on today and according to a few searches there is a light code I can trigger by shorting out some wire and that code will tell me whats wrong.

1. Is this a hard thing to do or can I do it myself? If so how?
2. Would I find the codes in my manual or online?

 

you can always bring it to a local autozone. and they will use the scanner and check it for "free"

 

I think the is a procedure in the owners manual for getting and error code, that might lead you to the problem. may be nothing...

 

I know on my 94 accord there is a blue 2-prong plug underneath the glove box that can be shorted out by connecting the two parts with a paper clip, and the check engine light blinks to show the codes. Dunno if its any different for the 6th gens.

 

do a search, someone had a pictorial description on what to do and how to do it for a 6th gen recently.