Lude Generation

Hi all after scouring the land for a cat for my car I've came to the solution of getting a custom made job but until I raise that cash for the I could really do with a standard one as I use the car almost every day and it just ain't running right and basically want to start with lamda sensor and cat and work up to smooth running. I know they are hard to get second hand without them turning to dust at flanges and not working either! As mine is! But you never know...