3 wire 02

[fl327]

wondering if anyone is running one and if they notice a difference performance wise, when i finally replaced my 02 i noticed that at cold start, it takes a minute or two for the o2 to start leaning out my idle, and for the first minute it will idle a little rough, and i dont mind this all that much, but i like the idea of my o2 metering me lean right off the bat at startup, and was wondering what other characteristics that a 3 wire would have that would justify me breaking out the funny socket....

[Len]

I installed a 4 wire. It really didn't improve my fuel mix at startup. All the 3 and 4 wire has different from single is a heater that heats up the 02 sensor faster to get readings sooner. (grey-signal, black- ground, two whites-ground & keyed positive). Personally I have gotten better readings from my A/F gauge. Probably because you have a better ground which you are tying in your 02 sensor.

I would think what you are talking about could also involve your temp. sensor.

[TimZ]

I guess I don't know what engine controller you are using, but cold start is pretty much always run open loop. The O2 feedback usually doesn't start until the engine is warmed up. In fact, even on warm start, there is usually a fairly large delay (30 sec or more) before the feedback gets enabled.

 

Also, both the 3-wire and 4-wire sensors have the heater. The extra wire is a dedicated return for the sensor signal, for reduced signal noise. The 3-wire uses the engine block for the return (common ground).