If it has a cat, it'll have a lambda AND it won't be a PB motor. There will also be an electrical connection going down to the front of the exhaust for the lambda.
As far as I'm aware the Golf2 GTI was NEVER sold in the UK with a cat- the changes to the RHD would have been two extensive in the final year of production, with the Golf3 in the wings.
The Jetta limped on a while longer, so may have had to had the cat fitted, see previous comments in previous thread.