2005 Dodge Magnum - Cat replacement

I am looking at having to replace my right side catalytic converter for the third time after exactly 2 years almost to the day. I bought the car in 2016 and had to replace both converters 2 years later with all sensors. This replacement exercise is occuring almost exactly every 2 years. I have the feeling that this car has another undiagnosed problem that is causing this. We use this only for long trip driving, not intown, and have always used the recommended 89 octane, brand name gas. This is an Magnum RT Limited Edition, 5.7 Hemi, no AWD. We have put 45,00 miles on it since purchase i 12/16. Anyone have any info to help me figure out what is the problem? Thanks.

Consistent with engine (for currently unknown reason) forcing too much raw gasoline into exhaust stream. Raw gasoline burns up in the cat, and the overheated cat eventually fails.

This would usually show up in a fuel trim test, and ID the problem to the right side bank.

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After market versus oem or engine tune but why replace it if it hasn’t rusted off?



How much oil does the car use? High oil consumption kills cats.

thank you.

Uses no oil between changes. I watch it carefully. Thanks.

When the cats were replaced, what did the substrate look like?


Orig engine but my mechanics - from whom I bought it - did significant work due to previous owner allowing it to overheat due to coolant leak. I am very pleased how it runs and fuel use…mid 20s at 70mpm on cruise control on interstate. no overheating, no leaks/drips of any kind. Reg synthetic oil changes less than 10k miles watching intervals. thanks.

from what I discussed with my guys, all looked good, all new after market. They are very particular about what they sell me. I’ve been with them for almost 50 years…Any suggestions on brands…thanks.

I installed Walker cats.


Thanks. Any particular one…model #? How long did they/have they lasted?

I installed them in customer cars.

Never had a come-back.

Thank you. I’ll have them get me whatever choices Walker has to offer…and not the lowest end model. Thanks again.

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