Anti Pollution Fault!!?

I am new to the 206 Gti group, but have been using this site for fixing lot's of little problems with my 206 Gti. It's been a huge help.

I need advice on the 'Anti Pollution Fault' my car is coming up with on the screen.

It also has a huge misfire and hardly any power - not sure if this is all connected to the anti pollution fault. I have changed plugs and connections, but no improvement. I have read something about changing the o2 sensors and fuel upgrade but not sure if this will fix the problem.

Also my engine shakes like crazy when I turn the ignition on, then calms down after about 5 minutes (But still way too shakey).

Any help on this problem would be great.