Help with exhaust flange

Hey guys sorry for my first message to be needing help but can anyone suggest the best way to get through mot the flange on the end of my cats has just GONE it was dust of its former self and I looked at the price in the UK of a replacement cat and nearly fainted (tis an 06 2.0 petrol estate) I'm way out of my depth here help!

If the cat itself is good, have an exhaust shop cut off the rusted end and weld on a new one. Just keep in mind there may not be enough good metal to build on. In which case buy a cheap aftermarket cat; they're generally good for about 3 years.

Try the local Subaru boards or post on the UK/Europe board (on this site) looking for a used pipe. A number of US owners take off the stock downpipe and replace it with a performance part. I know your MOT is a lot tougher than local state-by-state inspections in the US. I believe some WRX vehicles use the same part as your car but if your car is a manual gearbox, make sure you get a pipe from a manual (or automatic needs a pipe from an automatic).

Not sure how regulations work there, but you could have it sleeved. An exhaust shop can cut the flanges and weld in a piece of pipe. If the flange on the intermediate pipe is still good, it may be best to find a used cat. Welding a piece in would require both components to be replaced if you run into another issue later down the road. A good sleeve job will last as long as the quality of the piece of pipe they use.