2005 Volkswagen Polo egr valve

had various problems with tickover and running etc car virtually undriveable, plugs, ignition, coils, compressions, all ok, had car put on local garage dianostics in an attempt to find a solution they cant trace fault but EGR keeps coming back up on the fault codes they just charged £65 and suggested I take the car to the not so local VW agent,with the EGR in mind is there any point in removing the valve and attempting to clean it or is there nothing that cleanable inside valve, I know that the EGR valve is always being blamed for various faults on the BMW website anybody know the situation with Polo's