So I've finally got my old (18 months old) cat replaced with an aftermarket part. It cost £450 instead of the £1100 that Merc are charging. All seemed fine for a week, but now my engine warning light has suddenly come on. The manual says that this means a fault in the ECU, electronic ignition or the emissions are too high. The engine's running fine. My question is, how on earth can it know if the emissions are too high? It can't have detectors at the tail pipe so it must be measuring somewhere near the engine - i.e. before the cats. Any ideas?
PJH
MB Enthusiast
You could ask a garage to do an M.O.T. emissions test for you. You'll have the results on paper. Could be that the detector is faulty.
