Spark Plug Stuck...

Changing spark plugs today, I got the first 4 replaced without a problem. When I got to the fifth (middle plug on firewall side of V6 engine), the plug was apparently broken - the ceramic part was in the wire boot. I tried to remove the thread end, but it just keeps turning and never comes out. What do I do?

There may be chips of the ceramic part down at the bottom of the plug well that are preventing the socket from slipping over the hex part.

Try blowing some compressed air around the plug. Use a flashlight to take a look in the area (use a small mirror if you need to, to take a look).

Try to remove the broken part with a long large plier. Don't turn it, just pull it with force.

Be careful when removing this one....I broke one off in the head one time, a bad experiance. After you get the broken ceramic off like suggested, spray some penetrating oil on this thing and let it sit a while since you already have some damage there....just in case. Might not be needed but a good idea when removing plugs that have been in a while.

one of my biggest fears in transverse v6 or v8 FWD engines...

GL with all the suggestions!

Got them all changed - thanks for the suggestions! Penetrating oil did the trick. They smoke a little now because of that, but that will go away.

Changing the plugs did not fix the original issue, however. The car is chugging - it sounds and feels like a go cart. Not sure what's causing that...

Maybe a coil. You have 3 coils in your coil pack, check output and input resistances.
Check also CKPs voltage pulse. Check also continuity of the spark wires.

Replaced the wires, too. No change, unfortunately.

1. The car chugs. It sounds more like a go-cart than a car.
2. There is a smell of gasoline and sulphur after driving for a while. (Catalytic Converter?)
3. The oil pressure rises significantly when I am on the gas, and drops significantly when I am not on it.

Do you think this is the catalytic converter? Would that make the car run this rough?

If not the cat, what else could it be?

No, it's not caused by a bad catalytic converter. It sounds like bad valve guide, have you done a compression test? Low compression can cause the engine to sound like a 2 stroke motor or run roughly.

Why do you suspect the catalytic, you have water spill under it or blue smoke? Exhaust noise?
Do you burn oil?

The catalytic converter reduces emission only.