catalyctic converter

i just got a 91 honda civic si 1.6l its making a funny noise like something
is rumbleing inside the catalyctic converter. i wanted to replace the part
but i noticed that the catalyctic converter only has two bolts in one side
the other is welded to the pipe that leads to the muffler. i dont know what
to do.

 

is there a heat shield that could be rattling?

unless you need it to pass smog, i wouldnt mess with it. chances are the
ceramic honeycomb inside is broken and thats whats doing the rattling.

 

and as far as replacing it, you have to cut it off and either bolt on a
replacement or have it welded on. best bet it to let a muffler shop tack it
on for you.
KH

 

if its just the heat shield would it make it easyer to fix? and iam afraid
i dont know what a honeycomb is. can you tell me?

 

Are you the original owner? Sounds like the converter might have been
replaced once already. On my '87 Si hatchback, when I had my cat
replaced, they just cut off the shield, cut out the cat (torched), and
welded in a new one, sans shield. Took them all of about 5 mins. If
this is the case, just have some muffler hack do it again. It's
almost impossible to replace bad exhaust parts/tubing that's been
welded in unless you can add new tubing at a point that has a good
virgin tubing to clamp to.

nb

 

Your catalytic converter is basically a metal box with a honey comb like
ceramic inside it that when it gets hot cleans the air coming out of your
exhaust. It has to get hot in order for it to clean the air so they put an
extra layer of metal over it for a heat shield. The ceramic inside your cat
can break and eventually plug up your exhaust. so either your outer layer of
metal is just loose or your ceramic inside is broken. If the ceramic is
broken then the only fix is to replace the whole cat. Symptoms of a plugged
exhaust are a significant loss of power.

You sound lost enough that you should take it to an exhaust shop and just
let them fix it. At least you will know exactly what they are talking about
though.

Here are pictures and a thorough explanation:
http://auto.howstuffworks.com/catalytic-converter2.htm

KH

 

If the heat shields are loose, you can easily tell by getting underneath
and wiggling them.

A big hose clamp will snug 'em down and keep them quiet.

Forget that. Chances of the cat's internals being broken apart are
*extremely* remote. Heat shields rust loose every minute of every hour of
every day.

 

thank you all. i have learned alot from all who responded. thanks again.