The CAPS question will probably need Joe to answer...

But the exhaust question: the cat is for smog, bypassing it won't effect anything upstream other than perhaps cause you to now have not enough back-pressure to idle as well. As long as the O2 sensor is on the downpipe (and working!), the carb will read the exhaust just fine.

Don `87 Mitsu 2dr, Rubicon survivor, GModified.