I had the same problem with my c5 2.2: the antipollution alarm and the ebs fault where on. In this condition the computer sets the max engine speed to 2200 tr/min. After long troubles ( more than a month) the citroen was able to fix the problem, it was a pipe boken in the intercooler. In this condition a pressure sensor reads the wrong air pressure and the main computer gives the antipollution alarm. Check carefully the intercooler pipes (in my car was broken a small rubber pipe having a cost of few penny). bye Andy
