How does one "maintain" this unit, if in fact it can be maintaned?

How does one know when theirs is at the end of it's line?

 

To my knowledge, you don't maintain a cat. you just replace them. a worn out cat will give worse mileage and sometimes a buzzing sound. or it won't pass emissions. getting a legal high flow cat would be a good replacement with a little extra power.

 

I had a cat converter go bad in my dodge dakota awhile back, and it had a hideous rattling noise coming from it when accelerating, especially from a dead stop. As far as maintanence goes, I dont believe they require anything special.

 

My Ram (last vehicle) is now on it's third cat. It was originally replaced under the 80K mile exhaust warranty. The second one was replaced 25K later. Stupid Dodges...:pat:

Yeah, no maintenance. Hopefully soon I'll have my high-flow on.

 

A cat is quite possibly the lowest maintenance item on your rig. It's either in working condition or it isn't. With that in mind, there are a few tell-tale signs that your cat is on its death bed:

* the rattle of doom. If all your hangers, clamps, heat shields are tight and there is still rattle coming from the converter, its' time is almost up. Basically, what's happened is that the monolith or honeycomb inside has broken free from the shell of the converter. The cat is no longer ready to oxidize the foul stuff in your exhaust, but would much rather start to rattle itself into little pieces that will eventually clog up your exhaust system.

* the stench of sulphur. Some cats plug up from time to time for a variety of reasons (improper tuning, old age, the use of leaded fuel), and often these plugged cats smell like sulphur or rotten eggs. If your exhaust smells like sulphur and you're seeing diminished performance, get that cat replaced quick before any other damage occurs.

If your cat does need replaced, be sure to look for a high flowing replacement since they're usually priced competitevly with OEM style units. [Or if you're not a good citizen, I suppose you could always "gut" your cat or replace it with a piece of exhaust pipe. However, that's a decision that you and your state emissions program should mutually agree upon.]