Is there a way without any special tools or gauges to tell if the cat. converter is partially plugged?

I'm thinking my low power, low top end speed may be the cat. I am getting a sulphur smell sometimes too not strong and it may be in my imagination as I'm smelling it only after thinking my cat could be bad LOL

 

This has been addressed many times before. Get underneath it and rap it with a mallet or your hand. If you hear a rattle it means the insides have burned out and are lying in it. Wait too long and they will migrate to the muffler and plug it, too.

 

Hold you hand over the tailpipe and feel the gas flow coming out. If its little to no flow its stopped up.

What are the miles on your cat? From what you describe its classic symptoms of a bad one.

 

Many exhaust shops have the proper tools to diagnose a catalytic converter issue. They can run an exhaust back pressure test to compare the pressure before and after the cat and compare their readings with known good values.

 

Thanks for the replies everyone.

I have read on here to tap it and listen for a rattle. I apologize for not mentioning that mine doesn't have a rattle, but I still suspect it, that's why I posted.

I just figured my MPG a few days ago for the first time since owning it. I'm getting 9.5 MPG. Since day one, I always thought it didn't have a lot of power, especially after reading on here how the 4.3 Vortec is somewhat of a high performance engine. I can hardly go faster than 70 on the highway.

Full tune up has been done, no apparent gas leaks, no gas smell anywhere under the hood. I've had an annoying but minor surge/miss, fuel pump tested with gauge and maintains 60psi.

So a few days ago I started smelling something strange. I've never smelled a bad cat. before. I know I've read it supposed to smell like rotten eggs sometimes.... truthfully I don't think I've ever come across a rotten egg before LOL But I think I'm smelling something similar to sulfur faintly.

I live at least 45 minutes from the nearest garage/muffler shop that can properly test it.

Right now it has approx 93800k miles

 

If you figured it correctly, that's bad. I get about 20mpg highway with my 01 Blazer.

Blazeme