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Cat falure is common but using a scanner other than VW OEM or VAG COM, you may only have part of the story and there may be other codes present that also cause the cat code. Also, most aftermarket cats do not last so before you spend the ~ $1000. on an OE cat, have the car properly scanned. Also, many VW have an extended warranty on the cat...you can check at VW.com but better to call their recall hotline as not all show on line