Engine management light permanently on. Dealer says it needs a new catalytic converter as a result of damage due to misfire and faulty coil pack (since replaced). This is a twin cat model so replacement is a cool £1,500+. However, it still passes emissions test for MOT so we have left it. It is a 55 plate and so isn't worth that much and aircon is also not working. Is the EM system too sensitive? Should we repair it, ignore it and carry on and drive it into the ground (not very keen on this idea) or sell it with its faults?