hello new guy here. i have been told by the garage that i have a dead injector on number 4 but i am in two minds about keeping the car or spending any money on it so i have a sting of questions so as to help me make up my mind. 1. is it better to try and replace one or should i replace all 4 and the fuel rail? (http://www.ebay.co.uk/itm/FORD-FOCUS-MONDEO-ZETEC-1-8-1-6-16V-1998-to-2004-FUEL-RAIL-INJECTORS-/181357538625) 2. will replacing the injector and going back up to 4 cylinders sort out the horrible fuel economy? 3. is it particularly hard to do? i know which end of a spanner is which but am not a mechanic 4. does anyone know where the part number is on mine so i can check or if there is a way to check the one i found on ebay is definitely the correct one as it seems cheaper than others. thanks!