Ford Repair: 91 Explorer, clogged catalytic converter, wire bundle

Question
I have a 91 Explorer, 4.0L, 4x4, 5-speed manual.  I have been going through plug wires about as fast as I can change them.  I replaced the coil pack and am still running very bad.  It has no power.  I was at NAPA looking for what I believe is the radio noise control.  It's a small cylindrical shaped part, that has a single wire with a one prong connector located at the center of the front of it.  The wire runs from the same wire bundle that is going to my coils.  I don't know if this could have any effect on the way the engine is running or if it may be something else.  The guy at NAPA suggested a clogged catalytic converter.
I appreciate your time and help

Nate

Answer
Nate,

The part you describe is a noise capacitor and I doubt it is related to your problem. You can unplug it since the engine will run fine without it just to verify.  Yes, you may have a clogged catalytic converter. You can unbolt the exhaust from the manifolds and drive the truck to see if it runs any better.  How does the exhaust flow look & feel at the tailpipe? It should be strong enough to blow the grass over when you rev it up.

Good Luck!!!