You don't tell us which engine you have. Decent fuel would help the poor thing - Shell V Power or BP Ultimate are both good. I would never use supermarket fuel in ours. I assume that it has been serviced correctly.
I'd start by checking the air filter to make sure it is not filthy or wet.
If not that then I'd look at spark plugs and possibly coil pack. Make sure you are using the correct Bosch plugs obtained from your main dealer. Peugeots tend not to like other makes.
Also make sure there is no hissing from a cracked breather hose, that could upset it..
If it is a 2.0 engine there have been issues with tappets but I'd go through the more obvious points first. Deal with one thing at a time.
ChicksFan
February 2013