Problem with computer on 88?

My 88 Si is STILL running rich...even after I replaced both o2 sensors. I also bought a air/fuel ratio gauge and it reads 2 bars above the middle even when I am at an idle. Any ideas? Is there a way that Honda can hook up to the computer and change the fuel settings so its not sending so much damn fuel into my engine? Or is there some other possible culprit? This is pissing me off...please give me some info if you have any. I also bought a new CAT, but I'm waiting to put it on til i even out my fuel. Carbon is coming out my tailpipe, so no sense clogging up a new CAT right away. CAT don't lead to cars running rich, right? Someone at Schucks told me they do, but I've heard otherwise from other people. Any help would be appreciated.

Drew