Lost what little power it had?

[mpire]

I have a 97 ranger with I think a 99 2.3 engine swap with 80k miles on it. Probably 180k on the chassis.

Coil packs, plugs, valve cover, wires, water pump, belts, hoses, etc have all been replaced in the last couple years. 5 speed manual rebuilt recently.

Cooling doesn't look cloudy, not low on oil or coolant.

I was driving home the other day and the alternator crapped out on me.

I made it home on the battery, but towards the end there wasn't enough juice to fire the coil packs, I guess. Not really sure. But it wasn't firing on all cylinders for sure.

Dumped a lot of fuel into the cat and it was bright yellow when I got home. I could see the glow under the truck and it was like I had LEDs underneath.

I replace the alternator, charge up the battery, and everything seems fine.

I go to a show with the gf and there is a really steep entry ramp into the parking garage.

Poor old ranger just can't get up the ramp in first from a stop. Not enough power. Pretty sure I haven't had this issue before.

Every once in a while the engine hangs at an RPM while in neutral when I'm puttering around.

So I am about to replace the cat thinking it has to be clogged. Everything looks good, no engine codes, fires right up like always.

Got any ideas?

 

[Uncle Gump]

Google testing for a restricted exhaust with a vacuum gauge. That will tell you if the catalytic converter is plugged.