A smog check repair station will first have to find out if your Mitsubishi Montero's fuel feedback system is working properly.
Fuel feedback sensors such as the MAP, MAF, ECT and O2 sensors need to be diagnosed in order to ensure your Montero's emissions computer is receiving the signals from these components, the computer is computing the data properly and sending the correct signals to the fuel injectors to either increase or decrease fuel delivery to the combustion chambers.
For more information on what causes high HC please follow the link below:
What Causes High HC?
