Hi, new to the forum as I have recently brought a 04 Clio 182 however Ive come across a problem... the cat needed replacing and post cat lambda sensor wire had cut so I needed a new one so the two lights came on. Yesterday I got a new cat and also rear lambda sensor however lambda sensor was second hand. Now the two lights remain on, Ive tried the little dash diagnostics thing and no errors came up and disconnected battery for half a hour and the lights remained on. any advice please?