injector or system

Towed my car and started it once we stopped the engine sounded like a bunch of empty bottles being hit together really loud rattling, prior to this all I did was change the turbo, put new seals in the Injectors, new fuel filter and changed the fuel lines the car has drove with plenty of power...

Hi can anyone recommend a good fuel injector/system cleaner product, for my mk2 leon fr tfsi with a ko4 conversion etc also what brand coolant do you use ? Cheers Reesy