my em light has come on and because my car is still under warranty I took it back instantly. After doing test I was told it was because my car had been decated which I knew nothing about. They said they would replace it with a proper cat, but they are having problems because it's a complete scorpion system and they are saying the cat will fita the manifold part but not the rear. I thought cat is a straight swap, after reading other posts about swapping for mots. Can this sometimes be a problem then? Cheers