UK Car Repair Questions? Ask a Mechanic for Answers ASAP
this may be an issue with the FAP system
In the exhaust is a soot filter known to PSA as a FAP. It runs very hot to burn some of the soot off every few thousand miles. It uses an additive is called Eolys and is stored next to the diesel tank with a computer controlled dosing mechanism.
If you don't drive it long enough, fast enough; then the regeneration process won't commence and the filter will block. Take it for a 40 minute blast down a empty dual carriageway; As you need to maintain above 50mph for around six minutes - that will start the process.