been getting a check engine light lately, comes on for a min or so then goes away. im thinking it may be an o2 sensor, i dont know if it would cause it but i just put a downpipe in and deleted all the cats but the rear pre cat. and of course mine has the obI computer so it cost a fortune to get checked.

 

i belive you just hook up old style voltmeter to it and see what the code is. There is a manual somewhere online, i have a copy printed. I think "thestealth" posted a link to it at one time \
EDIT: found it, http://www.stealth316.com/2-diagcodes91-93.htm