Chip tuning
If you chip tune the engine in your vehicle, this must be approved by the NPRA and entered in the Vehicle Registration Certificate.
If your vehicle has been chip tuned without subsequently obtaining approval from the Norwegian Public Roads Administration (NPRA), it is illegal to use the vehicle. You risk having its number plates removed by law enforcement if you are pulled over for inspection. This applies even if the tuning was done before you took over the vehicle. The person using the vehicle is responsible for ensuring that the vehicle is in proper and prescribed condition.
Tax
If you are going to chip tune your vehicle, you will in many cases have to pay an additional tax. It is your own responsibility to check whether you have to pay taxes. Check whether you have to pay extra tax on your vehicle (Norwegian Tax Administration).
Chip tuning may result in illegally high emissions
Chip tuning means that the vehicle will have a new engine control unit / software that increases the engine power. Chip tuning will in many cases result in higher emissions than what the vehicle was approved with. In order to have a chip tuned vehicle approved, you need to present documentation from a government-approved testing authority that the vehicle still meets the emission limits. Such testing authorities may be TÜV or Dekra. There are no such testing authorities in Norway.
Many companies that offer chip tuning cannot document the resulting emission levels. If you have a chip-tuned vehicle without approved documentation of the emission level, it will not be approved upon inspection.
Other technical requirements
In order to have your vehicle approved, it must satisfy a number of requirements applying to brakes, tyres, noise, emissions etc.