I've been looking at O2 gauges and I'm confused on the difference between wideband and narrowband.

Am I correct in thinking that one of those cheap $60 guages can connect to my exisiting O2 sensor? I'm just needing basic lean/rich readouts at the moment. What's the benefit in getting a full wideband sensor?

 

yes the $60 will connect to yours, but connect it near the ECU, not the O2 sensor. If you just want basic readouts and dont plan on tunning off it then it will work fine

 

if you use the O2 sensor for the gauge then how does the ecu get the signal? I want one of those guages, and a boost gauge for my turbo II. where's the best(cheapest) place to buy gauges?

 

you splice into it, you dont cut it.

 

I'll try to answer the second part of you question. From what I understand, the O2 sensor gives a reading in voltage. A narrow band reads between 0-1 volts, where as a wideband reads between 0-5 volts, so there is better signal signal resolution. This allows a more accurate reading and give the ability to more finely tune the engine.

 

i think you also need a wideband o2 sensor

 

i think the ecu doesn't use the O2 sensor under WOT. thats what i read,

 

That's a small part of bit, but that's not the real difference. A narrow-band sensor is called that because of the shape of it's output. It changes rapidly from low voltage to high voltage around stoichiometric, meaning it's only accurate in a very "narrow band" around that point. That's fine for what the stock ECU uses it for.

Once you get further from that point though accuracy suffers, as the narrow-band sensor's output varies greatly with temp. A wide-band sensor must be connected to some fairly sophisticated electronics in order to compensate for exhaust temp variation. This makes them suitable for accurately measuring rich mixtures under full load, something a narrow-band sensor and gauge cannot do.

Narrow-band gauges connected to the stock O2 sensor are fine for day-to-day driving, allowing you to monitor the engine's general behaviour and spot changes that indicate a problem. It you want to do tuning, a proper wide-band set-up must be used.