How would I go about installing an Air/Fuel mixture guage in my car? I would really like some detailed information. See signature for list of my mods.

 

You would find a place to install the A/F gauge, hook it up to power and ground for the lights and the gauge, then connect it to the signal wire from one of your stock, narrow-band O2 sensors. Purple/white wire, PCM pin C20 for the drivers side pre-cat O2; purple wire, PCM pin C8 for the passenger side pre-cat O2. Or you could run a wire from each of the pre-cat O2 signal wires to a single-pole/double-throw switch, allowing you to connect either to your A/F gauge.

After you have done all this work, you will have a gauge that will provide very little in the way of useful information, other than that the O2 sensor either is or is not working. At part load/part throttle (closed loop) driving, the O2 values will swing wildly between "lean" and "rich" several times a second, providing little more than a psychedelic light show. At WOT, the gauge will indicate "rich". Which means??????

The stock narrow-band O2 sensors are only accurate at 14.7:1, because that's where the PCM controls the A/F ratio in closed loop, to give the catalytic converter the mix it needs in order to minimize emissions, and which also gives you decent fuel mileage. But you need a much richer mixture for peak power/torque, and the stock sensors are not accurate at those levels.

 

AEM has a nice one that gives you an actual A/F ratio...I think Jegs has it, but its like $300..Its supposed to be accurate. The shop I use has them on their blower cars...I think it comes with its own O2 sensor.

--Alan

I think this is it:http://www.jegs.com/webapp/wcs/store...0625&langId=-1

 

There are numerous outfits who make "wide-band" O2 gauges, complete with wide-band sensors that need to be added to the exhaust system. These renge from $300 for a single channel up to well over $1,000 for a dual-channel setup. The AEM is one of them. The Innovate Motorsports LM-1 unit is popular. If you are interested in a wide-band A/F gauge, do a "search" in the "Computer Diagnostics and Programming" forum.

The wide-band is accurate because it is designed to cover A/F ratio over a "wide" range of 10:1 to 20:1..... but the cost it high.