Red Hot Cats?

I think when they glow it means they are clogged.

Do you still have the air pump

You can use a manifold vac gauge to test for an exhaust restriction. Hold the RPMs very steady at 2500-3000 (in that range, but pick one and hold it rock steady) RPM and watch the reading. If it starts to fall after anywhere from 10-60 seconds, that suggests an exhaust restriction.

do you have the stock dizzy on it? do you have an exhaust leak? by the headers?

I had a similar issue with my 92 after leaving it parked for several months. I started it up, and it idled erratically. I left it running in the driveway for a while to charge the battery, and noticed that my cats were soo hot that they were melting the underbody coating onto the ground in puddles. After changing all the wires/rotors/plugs and cleaning the MAF, it still didn't fix it. I then pulled codes and saw my ox sensors were all pegged at zero. Read about that condition on this site, and one of the reasons was too much air going into the engine unmetered by the MAF. I started it up and really listened around the engine, and heard a sucking sound which I identified as coming from a broken hose connecting the charcoal canister to the underside of the intake. When I plugged this hose, the idle smoothed out, and the cats cooled down. So your sucking sound may be coming from a broken hose letting air in. You can either poke around up front while it's running, or buy a can of starter fluid to spray around the engine to locate a potential vaccuum leak. Good luck!

The diverter doesnt cause a tangible lean condition but it can deprive the cats of the air they need.