'96 Jimmy under body noise

[ventrca]

Rattle under the passenger side occurs as engine idles, but not so much or at all when in drive. I have checked for loose heat shields around exhaust system but have not found anything that would cause the noise.
Any other ideas as the causes?

 

[Smoky02]

possibly the cat...

 

[ferretx9]

possibly the cat...

That was the case for me .

For what its worth -
As I understand it the inside of a cat can break up & then the pieces travel
to the muffler & possibly clog it up . Just what a mechanic told me ...

An odd thing ?
When someone would push / apply a little steady pressure
to the exhaust system the rattling " went away " .
Maybe their foot was absorbing the vibration ?

 

[ventrca]

possibly the cat

If it is the Cat, other than the emission readings being higher than normal, should I have it replaced or leave it as is? Will there be any other problems to crop up if left alone?

Thanks!

 

[ferretx9]

For what it's worth -
I would replace it , yes it can lead to other problems .

You can search here or Google " back pressure cat converter " or " clogged converter " for info on what can happen.
And -There are some threads/ posts here that can help with the " how to / should I " type of questions .
: )

 

[Bingham]

its the converter.. have had the same problem, sounds like heat shield rattle. Only fix is to replace it.