Installing a 3-wire O2 sensor in a \'91? Hey guys, A friend of mine is selling me some Autometer gauges, and one of them is a Air/Fuel ratio meter. I emailed autometer's tech support, and they say that I need to purchase this kit which is basically just a setup to a 3 wire o2 sensor. The stock one is a single wire (non-heated which is what the 3 wire is for), and was wondering if anyone could tell me if a 3 wire o2 sensor would fit in the stock bung? Their kit sells for 90 bucks, and I'm buying the gauge for 10, so it seems kinda stupid to spend that much. Im also going to get headers soon, so welding in the bung they include into the stock manifolds would be even more pointless. The only thing the 3 wire does is heat the o2 sensor, so that it starts sending out the signal to the computer and the gauge, it has to reach 600 degrees before it can start doing anything. I was just thinking that maybe if a 3 wire sensor would fit, I could just fabricate a new harness for it. If anyone has a air/fuel ratio meter like this setup with the stock o2 sensor, or adapted to a 3, any help would be greatly appreciated.