98 mustang gt 4.6l cat converters

[darkstang]

i have a 98 mustang gt 4.6l and i dont see any cat converters on it any where. its dual exhaust, It has the sensors in the exhaust i can see them but other then that it just has the mufflers, and my check engine light came on and sayed catalyst efficincy below threshhold. code P0420. but like i said i dont see any catalictic converters no where. Why???? mabey aftermarket exhaust??? I was told by exhaust shop that they have an after market off road exhuast for this year that dont have cat converters on it is this true or did some one just take off the cats?. can any one help me with this question??? thanks