Hello, driving since 2012 a C5, Break 2,2 l HDI Bi Turbo built in 2007. Now 163000 km ran at purchase 72000 km. Problem: Onboard computer shows fault, exhaust system, engine control light and service light. Start car, engine lock immediately at 2000 tours, at stand gas 3000 tours. Let’s say at 10 starts the problem occurs easily 5 times. From and on the problem usually does not fix. Air mass sensor and valve are cleaned. Diagnostics are deleted. AGR V Entil is just new and he didn’t show any more errors, but one day later he did. Have read a lot of articles here because of exhaust system broken, but nobody had the problem that shuts down the engine. I know that problem can have quite a lot of causes, but I don’t like Citroen to put the money in the A…. Does anyone know the problem and can give me tips to narrow down or fix the cause? Thank you for the help. I hope I have all the information you need. Greetings Olaf