Is my Cat Converter bad?

I have a rattling coming from underneath...it seems to coming from the smaller muffler-looking thing that looks like it may be a cat converter. Its directly under the front passenger seat. i checked for loose clamps/connections but everything is pretty secure. From experience with another vehicle, when a piece breaks loose inside the cat converter, it sounds like a rattling. Could this be my issue.

I also have a vibrating noise coming from underneath that sounds like a loose cable. I've had this for a while...before the rattling noise. I only seem to hear the 'vibrating cable' when i shift out of park. (don't hear it while driving).

any idea what these issues could be?

much appreciated

 

While it could be the catalytic converter, I had that same noise issue 2-3 years ago in my 2001 2.4L AT and it turned out to be the U-joint, which I ended up having replaced. Just saying it could be that...

 

U-joint? not sure exactly what/where that is. can you point me in the right direction?

 

It doesn't sound like the cat, I just replaced mine and it didn't make any noises. The truck started to have some hesitation in the accelerator and the floor actually got really hot just from hard acceleration. Also it started to use more gas, but no rattling noises. Mine is a 1996-2.4 and it only has some screens inside of the cat, there are no moving or loose parts. So it's likely not the cat.

 

Check the heat shield? I had a rattling and it was from the bolts that held on the heat shield rustedaway and there was only like one bolt holding the heat shield on so the thing was flappin in the wind.

 

not the heat shield... everything seems nice and tight and secure. it actually sounds like its coming from the pipe that is connected to the cat canverter.

come to think of it...i'm not even SURE that what i'm looking at is the cat converter. I'm looking at the smaller muffler-looking thing under the passenger front side. i also see a similar one toward the front,,,by the engine.

 

You have 2 catalytic converters, they both look like small mufflers. The thing that looks like a big muffler after the second cat is your muffler

You are correct that it is possible for the internal matrix in a cat to break into pieces (it is ceramic) but that usually takes some sort of impact. Is the heat shield dented? Cats usually fail when they get clogged though, if yours was in pieces inside you would very likely have a check engine light too.

Th u-joints are the things on your driveshaft that connect each straight piece to the next, but allow the whole thing to flex while it spins.

 

I have seen vehicles with broken/bad cats and not throw a code but lack power when needed even up small hills. When looking under the truck hit the cat pretty hard with your palm or fist and see if you hear the noise. If you you do track it down that way.

The u-joint will be down the center of the truck attached to either end of the driveshaft(long tube that is not part of the exhaust). Try pushing on it in all directions and if it moves yiou may have a bad u-joint which is much easier on the pocket book then the cats would be.

Good luck.

 

Cats can be had for under $150 now, direct bolt in replacement (I just had to replace mine because the pipe leading to it rusted out)

Not cheap, but if you don't know how to replace a ujoint you're looking at labor too, so overall it would probably be pretty close.