Bad Catalytic Converter?

[nick0789]

Exhaust Rattle

youtube.com

I’ve noticed that after getting my exhaust manifold bolts replaced that I’m getting a little rattle from the passenger side with the engine running. I checked all the heat shields and everything is tight. When I bump the catalytic converter with my hand I get the rattle as heard in the video. I can smack anything else in the exhaust and the sound is loudest at the passenger cat.
is this sound indicative of a failing cat? I’ll try to get a video while the engine is running later, but I wanted to get an idea of what’s going on (or if I’m missing something) before taking time off work to take it to the shop.

 

[OR VietVet]

That noise is either the catalyst broke loose inside the converter or a heat shield that you cannot see or have not checked yet. If you do replace the catalytic converter, do both and if old enough, do all Oxygen sensors. This is only my opinion and the way I would do it, do just the one cat if you wish of course.

Soon, you will have catalyst break loose and get in to your muffler(s).

 

[nick0789]

Thanks for the reply.
If I end up having to replace the cat, I was going to plan on eating the cost and just replace everything at once and be done with it.
I checked the hangers as well and they were all tight so I’m worried that it’ll be the cat haha

 

[OR VietVet]

Did you look them up at RA yet? No vehicle info shared or I would look up for you.

 

[nick0789]

- 2005 Tahoe Z71, 5.3L gas

I looked at RA and am seeing $350-400 for a complete swap setup (minus O2 sensors obviously).

 

[OR VietVet]

Same rig as me. Are you saying you are not in Ca. and not a Ca. rig? If so then this will work: https://www.rockauto.com/en/moreinfo.php?pk=2598698&cc=1431156&pt=5808&jsn=911

Front O2: https://www.rockauto.com/en/moreinfo.php?pk=438154&cc=1431156&pt=5132&jsn=928

Rear O2: https://www.rockauto.com/en/moreinfo.php?pk=539430&cc=1431156&pt=5132&jsn=929

I have used Walker exhaust for years with great success.

 

[nick0789]

Here’s the rattle at idle, engine hot.

 

[OR VietVet]

If that is in park or neutral, try recording it when in reverse or drive. Sometimes the engine loaded will make more noise in there.

That is a better video and IMO sure sounds like something external rattling. When it is doing the noise I would crawl under there and touch everything and if noise still persists, then it sounds slightly different to me because it is just a noise that just started and not as bad as I used to hear by the time the rigs got to my shops.

 

[Doubeleive]

go by any muffler shop and see if they can tell if the cat heatshield is broken anywhere if so they can weld it, also a experienced employee may know right where to hit it with a hammer to stop the noise, your issue is not entirely uncommon. just annoying

 

[swathdiver]

Exhaust Rattle

youtube.com

I’ve noticed that after getting my exhaust manifold bolts replaced that I’m getting a little rattle from the passenger side with the engine running. I checked all the heat shields and everything is tight. When I bump the catalytic converter with my hand I get the rattle as heard in the video. I can smack anything else in the exhaust and the sound is loudest at the passenger cat.
is this sound indicative of a failing cat? I’ll try to get a video while the engine is running later, but I wanted to get an idea of what’s going on (or if I’m missing something) before taking time off work to take it to the shop.

Ok, so the noise happened right after the manifold was removed to replace the bolts? I reckon that there is a broken stud or bolt in there making that noise and if not removed soon it will take out the cat.