It should be OK but the lambda sensor may have suffered. I do not see cat failure very often although I did have a Passat 1.6 (same engine) in not long ago which had an AMM that had been disconnected for a very long time and even after a new lambda sensor, the cat would not recover at idle but was OK at fast idle. That particular car did not have a faulty AMM though, it had (I presume) a faulty lambda sensor and someone else had fitted two new lambda sensors but to no avail, it still kept coming up as a lambda heater circuit fault. I found that both of the new (and according to the manufactures listing, correct) Beru lambda sensors had too low a heater circuit resistance so the heater circuit was not consuming enough current. I fitted a new genuine sensor and it cured it (except that the cat was US) , sometimes pattern aftermarket parts can make your hair fall out…