I found my 3rd cat is clogged, removed it... And I'm now curious about straight piping and removing the 3rd cat and muffler.

What are the trade offs?

2004 Ford Ranger 3.0.

 

Cats are for emissions they make for cleaner air
Mufflers are for less noisy exhaust

Neither effects performance one way or the other, unless, like yours, one gets rusted out and clogs up.

So no upside or down side, unless you have to pass emissions test, then you have to have the Cat replaced

If you have kids you may want to replace the Cat so they have cleaner air for their future and their kids, yes, guilt trip, lol.

 

You need to make sure your truck will still pass your state inspection if you choose to remove the cat/muffler. In my state they only do a obd2 scan so it's no big deal. Ditching the 3rd cat doesn't change the way the vehicle runs since the 02 sensors are only reading from the primary cats.

I would advise against ditching the muffler however. Your truck will sound like a rolling dumpster fire and give you zero performance benifits.