I am back on forum

[Ianr]

That sounds like a plan - I'm not a mega techno but a cat seems to sort most of the issues. I bought a cheap weld in Cat from ebay which got my Mk 2 engine through with no problems, basically - any cat should do it although you can get 100, 200 and 400 cell types. The higher the number the higher the resistance but greater cleaning effect, mine was a 400 cell as I didn't want to fail IVA and does not seem to have much detrimental effect. And it only cost about £50

I take the point about you have an engine but maybe a replacement with a provable history would get you through IVA was my earlier point