Reaming out a catalyst?

[Kevin1]

The insides of our Spider's catalyst are coming apart. They rattle around inside the can and are making a racket. I plan to empty the catalyst and put it back, but am concerned about exhaust noise. No smog check here, so that isn't a problem.
With an empty catalyst will the car become noticeably louder?

[mbouse]

do you have a resonator pipe in the system?

i do on both our Spiders. when i put on a "test pipe" in replacement of the cat, i experienced no difference in sound or volume. i would expect an empty cat would produce similar... IF you have that resonator pipe.

[So Cal Mark]

an empty cat can act like an expansion chamber and create a little more noise, mostly a tinny sound

[dwcars0]

Kevin
I had the same problem. I removed the cat, used a pipe to knock the ceramic cells out and bolted it back together. There was also a resonator. The car did sound a bit different. Maybe a little louder and there seemed to be a resonance that wasn't there before. It worked fine until the muffler fell apart and I put a whole new system on. Dan

[azygoustoyou]

Kevin,
Too bad you didn't make this post one day sooner. I just cut up a cat yesterday that was like new just for the flanges. I would have traded you the cat for cat. I made a test pipe to replace the cat. Sorry bud. THough I still have the middle if you want it. All you have to do is weld the flanges back on. It might not be worth the ordeal. Here's what I did.

[wengr]

hey that looks great. How did you enlarge the ends of the pipe? and did you weld the flanges on?

[azygoustoyou]

I told Meineke what I wanted and they made the pipe for $15. I'll weld the ends when I put the exhaust on so I know it'll fit.

[Kevin1]

I'm going to give ot a try and see how it sounds. Anything has to be better than the rattling noises coming from it the way it is now. There is no middle muffler, (resonator?), only a pipe from the back of the cat to the muffler in the very rear of the car. Shopping around I found some slip on glasspack-type straight-through mufflers (remember Thrush and Cherrybombs?) that would fit if I cut the flanges off the pipes, making a kind of muffled test pipe arrangement. Will save that for if the empty catalyst turns out to not be a good idea.

[azygoustoyou]

The car I have came that way sorta. Instead of having the test pipe. It was welded straight through. It sounded pretty good. It did have a resonator also.

[saletto]

kevin - i was just reading your post about the cat. converter and was wondering what the noise sounds like with the converter on? does it sound anything like a loose washer/ringing? i experience this sound once the engine warms up a bit...it is there under power and when in neutral and it is driving me crazy.