Get the emissions test from the seller, definitely. I suspect it's unlikely it actually needs a cat but the e-test will tell you for sure one way or the other. Like I said, our Taco threw this code early on and it passed the e-test I got when I sold it by the fast track criteria, it was super clean. It was either the octane thing I think since I didn't do much else other than drive it, changed the air filter, change the oil.
'91 Toyota Pickup
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29
"They say the test of literary power is whether a man can write an inscription. I say, 'Can he name a kitten?'" -- Samuel Butler