Nissan Almera fuel leak/smell

No 3 cylinder coil burnt out so I had it replaced Iwas told to replace the plugs so I had this done too.Since this job has been done I have smelt fuel in the car.I cannot find a leak anywhere and the pipes seem to be in good order none are perrished or damaged.I took the car back to the garage where the fitter raised it on the hoist to inspect underneath .Still no leak was found.The fitter sugested I replaced the pollen filter as it was dirty !! Although I did not Have much faith in this Idea I tried it but the problem still remains.