I found this so maybe if it is my cat I can get it replaced for free
2. Clean Air Act Warranty Provisions (42 U.S.C. S 7541 © (3) (B))
The federal Clean Air Act requires vehicle makers to provide two emissions-related warranties -- a production warranty and a performance warranty. The production warranty requires the vehicle maker to warrant that the vehicle is designed, built and equipped so that it conforms with emissions requirements at the time of sale. The performance warranty requires the vehicle maker to warrant that the vehicle will comply with applicable emissions requirements as tested under state vehicle emissions inspection programs for the warranty periods specified in the law (for model year 1995 and later vehicles, the warranty is 2 years/24,000 miles for all emissions-related parts and 8 years/80,000 miles for the catalytic converter, electronic emissions control unit and on-board diagnostic device). The performance warranty is conditioned on the vehicle being properly maintained and operated.