diesel pergeot 307 hdi?

anti-pollution faults normally refer to a blocked catalytic converter sometimes called diesel filter there are two sensor pipes on the exhaust one before the cat and after these measure pressure differential so if the cat is blocked there is more pressure on the front sensor witch then via the ecu puts the fault on the dash.Your car may need to go to a garage for a cat regeneration.Or you could try running your car on the motorway to get the cat hot so it will clean itself try 60 mph in 3rd gear. Good luck.

Raz
January 2011