Check engine and low coolant light intermittent

[Galvaleo]

First thing that should have been down was pressure testing.... after the EGR cooler was replaced are you still losing coolant? Because is it possible you didnt burp get ithot enough and add more coolant after replacing the cooler? And if you replqced the cooler 3 days ago you should chexk your DOC and DPF because if your cooler qas leaking coolant internally then your DOC and DPF can be fu$ked causing back pressure that can be hurtinf your turbo.