I've had no issues with my Magnaflow cat replacement and its been on the wagon for about 50k miles now and passed CA smog twice, and AZ smog.

Cat's die prematurely due to oil consumption and bad mixtures. If everything is in check, a cat should last a long time. Of course though, the factory cat's are the best. But paying $1k+ for an OE cat is a little much.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k