Originally Posted by Berkshire_Crossfire
Good point! I've not had any warning lights come on.
If it is the secondary cats under the car then you will not get a warning light. Those cats are not monitored by the electronics. you can remove them and pick up a few HP. I am not sure how your cars are inspected in the UK and if this is an option.You said the rattling was coming from the rear? the second set of cats are under your feet. The first set which are monitored are up close to the engine exhaust manifolds.