Splicing into the O2 sensor
 

I am getting ready to install a Air/Fuel gauge and I have heard different sides of the story on where to get the signal from. Some say, FRWilk, to splice directly into the sensor, others say to splice into the DME. What is the best route to take? I am sure some of you have done one or the other. If I go the direct to 02 sensor, where do you go through the firewall? Also, where do you connect to the 12v ingnition source for power?

I find it easiest at the dme.

You may need to pull back the rubber boot....but its a nice clean connection.

A/F gauge = light show

Thank you for that input!!!:D

don't cut factory wiring
 

go to autometer web site and get a generic O2 sensor for like $20..then drill a hole in your exhaust..as close to the stock sensor and run wires from there...way easier. I put in an electronic air/fuel mixture gaugge and it works great....you may have to get a fitting to weld into the hole you drilled for the sensor to screw into...go to an exhaust shop..they"ll probably charge you like $30 to do it

I just installed a air/fuel gauge in my 951, but it isnt working properly. it shows nothing until about 4000 rpm, and then i get one red led, which is lean. could this be a faulty o2 sensor?

The thing is, you want to make sure your gauge is showing the exact same signal that's going into the DME. The cable going from the O2-sensor to the DME is a coaxially shielded cable. This is to reduce interference from the ignition coils and anything else out there. Unless you replicate this exact cable with the same impedance when you hook up your gauge to the sensor, most likely you'll be getting a different signal than what goes into the DME. The only way to ensure that your gauge picks up the same signal as the DME, is to tap into the O2-sensor line as close to the DME as possible.