So I finally got around to getting the catalytic converter replaced after two firms (one the dealer) told me it was gone after the EML light appeared. I went for the cheaper option of a welded cat as the main dealer advised going for a new one would be very expensive.
The cat was done yesterday and not long after I left the EML light came back. Brought it back today to be told that the cat doesn't just break and something causes it. Therefore, they would need to find that cause. After some testing of the emissions and reading the error on the computer - they told me that the lambda sensor has gone. They explained it regulates the emissions sent to the cat and newer modern cars have two of these. Apparently unless I get it replaced ASAP - I will damage the new cat. However, the part can only be obtained by the main dealer. They also said that there could be other problems and they wont know until this is fixed. They failed to properly explain why they never told me this in the first place or spotted the sensor was gone.
Does this make sense or am I being given the run around?