# What would cause catalytic converter to break up?



## Eagle One (Feb 11, 2011)

I am currently in a dispute with an online merchant from whom I purchased a remanufactured catalytic converter for my car. After having it professionally installed, I started hearing rattling from under the car a few days later. Long story short, the cat had broken up inside and became ineffective. Merchant says MY CAR caused the problem and does not want to cover under warranty. I beg to differ and my mechanic says it was a faulty converter. So, I pose the question, is there a way ANY car could cause a converter to break up (other than externally forced damage of course).


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## Windows on Wash (Aug 30, 2011)

External force, extreme temperature swing, and mechanical damage are the only 3 I would know of.


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## SeniorSitizen (Sep 10, 2012)

I think of this as recycling 202 at its finest.:laughing: It traveled to the scrap yard either legally or illegally and back into public service after being thrown around by the scrapper, his supplier and your vendor in recycle 101. You're up a creek without a paddle.


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## kennzz05 (Nov 11, 2008)

sometimes doing stuff on the cheap this is what you get


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## joecaption (Nov 30, 2011)

You bought a used muffler part!
Hmm.
To answer your question I can not think of anyway your car caused the problem unless it was back firing which is unlikely.
Just a bad idea on how to save money.


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## Nathan356 (Apr 13, 2012)

Running too rich or too lean can cause the cat to overheat and break down, although I'd be pretty suspicious of any "remanufactured" cat that broke down shortly after buying it.


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## SPS-1 (Oct 21, 2008)

Engine exhaust is very moist (water is one of the primary products of combustion) and obviously very hot. A good recipe for creating rust.


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## ddawg16 (Aug 15, 2011)

So....in the grand scheme of things....you saved how much by using a reman cat?

At a minimum, if the merchant honors the warranty, your going to have to pay to have the old one removed and the replacement installed.

You saved how much?


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## Eagle One (Feb 11, 2011)

OEM part from the dealer would have cost $1200. Remanufactured (exact external shell and fit with internal parts replaced) cost $300. I bought the car used for $6700. Hard to justify spending $1200 on one part IMO. There are cheap aftermarkets you could weld on for less than $100. I felt I went somewhere in between very cheap and very expensive and decided on the remanufactured one because it was the only one that would provide the EXACT sizing specs of the OEM. This decision was made after spending quite a bit of time researching the aftermarket converters for my car and reviewing the problems people had with some of them. In several cases, it seemed that the different size of the aftermarket could have led to issues. 

I have since replaced this faulty reman cat with a cheaper aftermarket made by Walker (from Autozone). It was about $100 and needed to be welded in. Three months so far and no problems. I hope that continues.


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