Air/Fuel Mixture Gauge

[schmaz356]

I was thinking of installing an air/fuel mixture gauge in my 1973 911 to help with the tuning of the MFI. This gauge requires an O2 sensor. Where is the best place to install this? the car has SSI heat exchangers. Do I need two sensors? Thanks.

[icarp]

just one sensor about 3-4 inches behind the 3-1 merge . make sure the sensor points away and clear of anything . weld in the bung and feed the wires and put the gauge in the clock spot
either side will work
good luck

[47silver]

I am installing 2 in a 72 to get both banks. Will post pictures when done

[tobluforu]

I have one, used it for tuning two other cars, along with my 72, but unless you are racing the car, there is no need to mount it.

[47silver]

installed 2 o2 sensors and 2 gauges,,for the 72 mfi.
something odd is occuring,
first start both sides run rich, then they 123 bank becomes lean (pegs the gage) and the 456 bank side stays at about 12.3,, that is at idle.
i cannot see how it could be pump related, and wondering if it is the o2 sensor.
,

[gumba]

I use to run 2 sensors, and ordered a dual a/f gauge from Westach. The gauge fit in the clock opening.
I’d swap the sensors and see if it reads the same.