I have had my Peugeot 407 2.0 Diesel for 2 years now, and every 5-600 miles, the engine develops a misfire, as if it is being starved of fuel for a second or two, then runs normally for a few seconds and then the cycle repeats. This happens for about 5-8 miles, and then it cures itself and runs perfectly for another 500-600 miles. I have replaced the fuel filter but it made no difference. I have taken it to a garage, but nothing is registered on the computer diagnostics.