Suzuki: stalling, suzuki sidekick, mixture problem

Question
I have a 89 suzuki sidekick fuel injected. I live at sea level and suzuki works fine. When I go north to higher elevation (3000)feet, it stalls and runs poorly. Any suggestions?
Thanks, Ron

Answer
The oxygen sensor is one of the main rich/lean modifiers, along with the temp sensor.  First, I would determine if it dies from low idle, or a mixture problem, keeping in mind that an extremely low idle can cause the oxy sensor to make the vehicle run rich.
scotty