Has any of you (or know of anybody) that is using the GM 4 wire O2 sensors for air/fuel meters? If so is there any advantage or disadvantage to using these? Thanks - Barry

I used a 4 wire O2 sensor for a while. The narrow band sensors are only accurate in a very narrow range (around 14.7) so it is difficult to tune with them, although it can be done. The wideband O2 sensor is way better, but in a pinch the narrow band can be used.

Originally posted by sneakey pete:
Has any of you (or know of anybody) that is using the GM 4 wire O2 sensors for air/fuel meters? If so is there any advantage or disadvantage to using these? Thanks - Barry The four wire types are simply heated oxygen sensors. Their advantage is that they can be located further from the manifold and pick up a more average signal from the 4 cylinders on a bank. The disadvantage is that they are just plain ol' narrow band sensors which only toggle between 14 and 15:1 or so. The wideband units on the other hand will measure from 8:1 to 20:1.

Thanks for the info guys. I wasn't sure on the band width. I knew they used different sensors before and after the convertor but wasn't sure what the difference was in them. When I put some in I will use the wide band ones, thanks again for the info. Is there a particular one that is better (cheaper) then the others?
graemlins/waving.gif Thanks again graemlins/waving.gif

Just beware that the wide band units require a module to run. They typically have 7 wires (so to speak) with two of the wires connecting to a calibration resistor inside the connector. One of the most popular sites on wideband O2 sensors is http://www.wbo2.com/ They have kits which are reasonably priced for a couple of different models of sensor. It's important that the sensor module is built to work with the sensor. There are two popular types - the NGK L1H1 and the Bosch LSU4. But if tuning is your goal there is nothing better or cheaper than a wideband O2 to do it. graemlins/thumbsup.gif