Can you use a tuning box and a remap at the same time on your engine? And if so, would you want to?
Two ways to look at this.
Fit the tuning box first and then fit a remap later
or put a remap first and fit a tuning box later.
Lets look at the second scenario first.
Fitting a tuning box after a remap.
There is no reason to expect this to work properly ie work without any issues such as check engine lights and possible damage depending on what parameters the remap has changed inside the factory ECU
Ultimately it will depend on the remap and what software is has altered in the factory ECU. As a general rule you have to assume a tuning box will not work when added on top of a remap.
Adding a remap to a car that has a tuning box
We are going to assume this is a custom remap and not a generic tune. There is no reason to expect the engine to have issues if the car is remapped with a tuning box attached to the engine. The remap will take into consideration the fact that the tuning box is active and the map will reflect the changes the tuning box is making.
The question that has to be asked is, why would you use a tuning box if you are going to have your car remapped? The changes a tuning box is making can also be done with a good remap, so you have to ask is there any reason to have the tuning box fitted?