Under the hood is a mess of vac lines. The only one you need is the one to the EZL ign box... yes, the rest are just emissions crap. Pretty shocking how clean it is under there once you delete all of that garbage.
There are three or four connections to the throttle body, I forget. Two run to those thermal activated switch valves on the intake plenum... from there they run to EGR and the charcoal canister stuff. I removed ALL of that crap, cut off the pipe tits, and filled with epoxy. One ran back from the charcoal stuff and I think one had just a cap.
The AIR pump stuff runs down the pass side of the intake plenum, just remove it all and put in trash. The tit on the intake plenum I TIG welded shut, I suppose a vacuum plug would suffice too. I cut apart the check valve down to a threaded bolt... yup filled with epoxy and reinstalled. There is no trace of the AIR crap on my car now.
EGR... well, chances are your tube if plugged shut from 25 years of carbon build up and it has not been functioning for years. It was on my ride. Just remove it all and cap the exhaust manifold. I also TIG welded the lower intake plenum hole where the EGR tube bolted down.
What plugs did you install... those +4 crap Bosch ones?
As MBdoc stated, HC is unburned fuel...someone may have adjusted the CO screw in order to compensate for vacuum leaks. These V8s really need a complete intake manifold reseal every 8-12 years. It is not too hard, just time consuming and typically very messy. You can do this over a weekend easy.
https://www.startekinfo.com/StarTek/outside/12253/disc%202/program/Engine/107/M117_56/073-013.pdf