Peugeot 206 HDI trembles on idle

My Peugeot 206 HDI trembles on idle and it costs to accelerate, I just did your maintenance service, already disassembled and clean the catalyst well, change the air filter but I don't know what else you have to do, I don't know if you will have to clean a valve or graduate something. This trembling makes it stronger when the car is cold. Any help will be very grateful