catalytic converter help

[Zac Carlson]

I recently aquired a 2001 Tahoe Z71. 5.3

I kept hearing a rattle from under the driver's seat, not loud, just annoying. When I apply pressure on it with a screwdriver while it's running it seems to stop. Could this be the cats or motor mounts or... Any advice would be greatly appreciated. Thanks.

 

[shreksbrother]

Hello, are you applying pressure with a scredriver to the catalytic converter and the rattling stops? Could be a few things:

- Loose exhaust (check for any exhaust leaks and give the exhaust a wiggle - when it is cool!)
- Broken heat shield mount (grab the heat shield and check for movement - again, when it is cool!)
- Internal failure of catalytic converter - the internals are honeycomb, and sometimes when the vehicle idles for long periods or is running inefficiently for a while, the honeycomb will become brittle and break apart, in which case the catalytic converter needs to be replaced

You could always just take it to an exhaust shop and have them take a peak... Most of the mom and pop places will put it up on the lift and give you an idea of what's wrong for free.

 

[Zac Carlson]

Thanks man! Honestly im trying to figure out what exhaust im going to put on it, a few of my buddies said to put some headers on it and no cats with a muffler. My buddy has that set up on a silverado 5.3 and it sounds great.