I own a 2007 Mitsubishi Nativa, which is basically the same as the Montero Sport but made for the Latin American market. I bought the car in Peru.

I lost the only key to the car while in a small mountain town. I had a duplicate of the original but it doesn't work because its not programmed and not original Mitsubishi. I bought a new original key from the Mitsubishi dealership in Lima and used the old key to duplicate the teeth.

Then I had some non-Mitsubishi technicians try to program the key for me but they couldn't get it to work. I think that may have been a big mistake because they didn't have the right software to work on my car...

I ended up getting Mitsubishi technicians from the nearest city to come afterward and try and program the key, but they couldn't program the key either. Their programming software comes up with an immobilizer error.

So I think that the car may have immobilized itself because the first technicians messed around with the system with the wrong programming software. The Mitsubishi technicians told me that the car needs a new immobilizer but at this point I am not sure if they know what they are doing.

Does anyone know if the car needs a new immobilizer in this situation, or is there another solution?