oxygen sensor? air/fuel gage?

i just bought an autometer air/fuel gage and i dont know much about oxygen sensors, which one do i need to get it working, i have one from an svo turbo mustang will that work?

Autometer seems to list several gauges and their website is not very good. Looks like you can get some that have the controller built in and some that dont.

Which one did you get? If you paid around $250 you should have the controller and sensor, if you paid less than $100 you likely just have the gauge that was meant to work with some other sort of ECU or controller.

The little bit that I know about the AFR gage is that what you really need for tuning a carb engine (or high performance engine in general) is called a "wideband O2". Kits usually come with the sensor and gage or cable to connect to a data collection device. They are also typically calibrated to the gage. Most use a certain Bosch wideband sensor. I found gages that come standalone are typically for fuel injected vehicles with some sort of ECU and use the narrow band O2 that is already on the car. I'm running an AEM UEGO wideband (p/N 30-4100) and is 'pre-calibrated' from the factory. Some other systems require you to calibrate the sensor to the gage during installation.

Not sure about the SVO will work or not. Is the SVO o2 senor 1,2,3, or 4 wire? You only need one wire to send the signal and the other wires are grounds and heaters for the o2 sensor. If you put the sensor near the header then the one wire will work, but you will have to let the motor heat the sensor to make at accurate (let the engine warm-up). Some newer car have o2 sensors before or/and after the cat which mean you will have to heat the senor ie 2,3,4 wire or sensor. The single wire sensor are much cheaper

I am using a "BOSCH Universal Oxygen Sensor #11027 1 Wire" $15 or so @ NAPA.. .works great

The sensor you need depends on the gauge you got - if it's a standard cheapo narrow-band A:F gauge then virtually any standard 1 or 3 wire O2 sensor will work. The sole difference between a 1-wire and a 3-wire sensor is the presence of a heating element. Since O2 sensors only work properly within a narrow range of temperature, sensors equipped with a heating element will be more accurate more often. The heater is just standard 12v - take one of the wires to ground, another to a switched (and preferably fused) ignition source. Some later cars use a 4-wire narrow band sensor that includes an "extra" dedicated ground; conventional 1- and 3-wire sensors ground through the exhaust system. If you find a 4-wire sensor, be sure of what you have as many 4-wire sensors are wideband and not the same animal. IME, stick with Bosch sensors - any of these part numbers will work with any narrow-band gauge - Bosch #13913, Bosch #13942, Bosch #13953. That first part number is a replacement for a standard fox body 5.0 Mustang; all should be available at your local auto parts store.

If you have a wideband gauge you need a matching sensor. Many wideband sensors are compatible, but not all. Be sure you get a compatible pair. I stick with Innovate gauges and sensors and they have never done me wrong.

A narrow band O2 sensor is really only good for giving you a rough idea of your mixture - it'll tell you lean or rich, but really not much else. For a daily-driven car where you just want to ensure it's in good running shape they are totally fine. Much of the last thirty years of cars relied on them, clearly they're not evil. If you're trying to extract maximum power, you're going to want a wideband - they will accurately and quickly tell you your mixture so you can fine tune your spark and fuel. In combination with a good EGT/pyrometer, you're set.

Finally, remember that placement of the sensor is important. With a narrowband sensor it needs to stay hot, so you want it as close to the engine as possible. Be sure it's not at the "bottom" of a pipe where condensation can collect on it - that can destroy the sensor. Mine is installed about 2" off the collector (170ci), above the elbow, facing generally forward - the only place I had clearance. Wideband sensors do not like to be hot - they need to be installed away from engine. In fact, assuming you're not running a catalytic converter, you can install a wideband at the tailpipe - just be sure it's the actual sensor in the exhaust stream and not the entire part! They are more sensitive to moisture, they do not want to be near the bottom of the pipe at all. Also, widebands run an internal heating element, and it's critical that heating element is hooked up any time the sensor is in the exhaust stream. If not, the sensor can become contaminated and die. If you're doing wideband, I recommend leaving it in the exhaust only for tuning, then pulling it out and sealing the exhaust back up. That's good practice. And, finally, all O2 sensors are sensitive to leaded fuel - so if you're running leaded fuel or lead additives you will probably enjoy a short sensor lifespan.

HTH.

Please reread what thesameguy wrote - it is very complete and consise. I very much want a wide band O2 sensor but have yet to splurge the $ for one.

I have used a narrow band O2 sensor for carb tuning in two cars including my Falcon. I get much closer with the narrow band than with traditional methods such as plug cuts. That said the question of how rich is too rich (or more importantly how lean is too lean) is difficult to determine with a narrow band sensor. On my drive this morning, the sensor was showing mildly rich up to about 50 mph and off scale lean at speeds above 65 mph. I have no idea if off scale lean is 15:1 or 18:1 (and that can make a world of difference).

Another way to think of a narrow band would be a blind man looking for an open manhole cover.
You know when you found it but you dont get any clues as to how close or far away you are.