Could be various things of course.
I'd start by checking your spark plugs and perhaps coils.

 

It's a diesel

You'll need live data reading using Peugeot Planet or Diagbox.

As stated, it could be one of many things, which is why the live data will be more helpful at pinpointing any issues.

Could be EGR faults, blocked air filter, blocked fuel filter, faulty injectors....

 

My 307 did this, it was the diesel temperature sensor.

But, it could be one of a dozen things that only a diagnostic will give clues to.


http://www.peugeotforums.com/forums...forums/general-discussion-2/how-contact-member-peugeot-planet-diagnostic-28190/


http://www.peugeotforums.com/forums/introductions-28/brief-faq-guide-new-members-83170/#post529130

 

As everyone else has said it could be many things and live data diagnostics while its running is best for diesels NOT read codes and fit whatever the code relates to as some garages do this rarely works.

If its not been serviced for a while do this first as it will be worthwhile to eliminate the basics.

 

Thanks a lot for the replies guys. It really means a lot with me being a complete idiot when it comes to cars. I know I have people here for advice. :thumb:

I'll report back with the findings after I send it to my garage.