I just confirmed it on my Toyota warranty guide. The muffler is only 3yr/36mi. The cat pipes are 8yr/80k miles....
Now you say you have less than 80k miles, but what is the date of first use of the vehicle, because that may put you out of the warranty period. If you want to PM your VIN, I can run it on Toyota's technician website (if you aren't registered on Toyota.com) and get you the DOFU.