Altitude Sensor Test
 

I have searched through the forums and find a lot of information on the altitude sensor and what it is for. However, my question is, I am at 5300' in Colorado. Car was running rough/rich, so went to test the sensor and found it at .6 Ohms. I forgot to reconnect it after testing and the car ran smooth without it connected.

Does this mean my sensor is bad? I know that it should be under 10 OHMS at altitude but seems strange that the car runs better without it connected. Not sure if the car is chipped. New to me 1976 911 with 3.2. Has new O2 sensors and fuel injectors.

Sensor seems good. It is a contact that should be closed (0 ohms) at altitude, which is what you observed.
No explanation as to why car runs better without it (contact open), except that maybe the ECU is chipped.

Thanks. That is kind of what I am thinking too. That it is chipped.

The factory altitude sensor being switched on should cause the injection to run leaner at altitude as there is less air density. If your car runs better with the switch disconnected (richer) I would start looking for leaks.

John

Or perhaps the injectors are dirty and need to be cleaned or replaced.