Citroen Xsara high emissions

check air filter change fuel filter and fill housing with forte fuel system cleaner take for good run using low gears to work engine make sure when tested that engine is hot i assume apart from the emissions that the car runs ok also avoid using cheap fuel use a good brand

Hi can anyone help? I have a small fuse box next to the main fuse box under bonnet,in it there is 2 40 amp fuses and 2 relays What are these for as 1 of fuses as melted.