Why does my car blow white smoke when I take off or turn it on and leave it on idle? I currently have intakw, intercooler, wastegate, catless downpipe, y-pipe, and protuned.

 

That is most likely condensation in the exhaust and should go away as the car warms up.

 

It's started this morning throughout the entire day 🤔

 

You could have the dreaded head gasket leak. White smoke is generally water. Is your oil brown as in muddy looking or do you see oil in your radiator? Is the engine generally running good or lethargic?

 

Is this common on Ecoboost Mustangs? I've heard of it on the Focus RS models and their Ecoboost but they are running a higher boost.

Not to fearmonger but here's a link to the article on this topic OP. Hopefully it's not the case. The Focus RS has the identical engine to the Mustang but with some mods to it. It's speculated that the mods on the RS are what cause the issue.

https://jalopnik.com/why-so-many-for...out-1820280550.

You can search "Mustang" in the article to see the exact items that are believe to cause the failures on the RS vs the Mustang.

 

you have got some good advice on here.
You had any time to figure out what your problem is yet.