DPF has to be coded out if you want to chip up! Of course you can chip up only in safe mode! You can get dpf exhaust pipe to repair factory's dpf! That is on ebay! You can get bmw inpa kit with cables and softwares from ebay and do it for yourself! EGR as well has to be coded out physicly repaired with different if it is broken! Good feature is popcorn limiter for diesel makes so sexy sound you can code chip for example for sport option on your gear box or for sport suspension button....
Take a look to hamann's website for exhaust pipe for diesel's! Just ask to make a copy somebody...will be much cheaper! You can take out catalysts if you want great sound in cabin but smell will be bad if you do that service must put cheater sensors on pipes