[johnconners]

I'm trying to tell if my catalytic converter has gone bad. Whenever I slow down at a stoplight after going about 40-50mph, there's a burning smell. It happens more often when there is more weight in the Jeep. I accelerate very slowly, but not sure if this a typical speed in a 4 cyl, or slower because of a bad cat. Any help would be appreciated!

[iwishihad1]

when my cat went bad, i felt like i was draggin a tree, and i got about 8 MPG (without exaggeration) i took everything off, and found a perfect side chunk had broken off, and clogged the outlet of the cat, i gutted it just to make sure it was the cat. and sure enough it ran great afterwards

i have a new converter now though

[johnconners]

Isn't it illegal for a shop to remove a cat, but its legal for you to do it yourself?

[Muddy Tj Zack]

It's illegal to run without one even if you do it yourself....when mine went bad It had no real effects on how it drove. But mine didnt clog up it just rattled really bad.

[RedefinedTJ]

mine makes all sorts of noise.... I need to ditch it soon

[barry1me]

If your 'cat' is rattling that means the substrate or converter brick is broken in to pieces. FYI if this is happening your taking a chance that it will clog your converter outlet pipe and either cause a loss of power, fuel economy, or even put so much back pressure on your exhaust system that your engine wont run. Im a Converter design engineer so we see this every once in a while.