You can't connect a wide-band O2 sensor to an ECU designed to operation with the older narrow band O2 sensor and expect it to work. It can't.
First, a narrow-band O2 sensor operates between 1.0V to 0.05V, and it "switches" voltage at stoic (14.7:1 air:fuel ratio for gasoline engines). A wide-band O2 sensor operates from 1.7V to 3.0V, and it gradually increases voltage as the air:fuel ratio goes from lean towards rich. The attached chart shows how the narrow-band O2 sensor and wide-band O2 sensor outputs voltage based on actual air:fuel ratios. Totally different. A narrow-band based ECU is looking for information in the operating range of the narrow-band O2 sensor, and all that ECU knows is if the ratio is lean or rich (the article says it knows stoic, but it really doesn't - it just knows on which side of stoic the O2 sensor information is - at stoic, generally the narrow-band O2 sensor switches frequently between 1.0V and 0.05V, which the ECU interprets to be stoic). The wide-band O2 sensor is linear as air:fuel ratio changes, so that ECU is programmed to know exactly where the air:fuel ratio is, and if the engine is under heavy load, light load, coasting, etc., so it can adjust the air:fuel ratio target for the operating condition. Below is a good write-up.
Narrow Band vs Wide Band o2 Sensors
A narrow band o2 sensor is an oxygen sensor that is only calibrated to know three things. Rich, stoic, and lean. What I mean by this is that it only has a narrow window that it see’s the air fuel mixture through. The sensor can tell the computer when it’s stoic. If it’s not stoic, it can tell the ECU that it’s either Rich, or Lean, but that’s it. It doesn’t really output any particular value other than that. How rich the car is the sensor has NO IDEA about. Same with how lean the car is. All it does know is that it’s not stoic. The ecu with a narrowband o2 sensor, when in closed loop mode, will then lean on the fuel map if it is receiving a rich signal from the o2 sensor till its stoic. The opposite would be true if the sensor was telling the ECU that it was currently running lean, it would richen the fuel map till the o2 sensor was reading stoic.
A wideband o2 sensor is much more sophisticated than a narrowband sensor, and can be relied upon to be used as a tuning tool. Wideband sensors not only are a lot faster acting in the reading, but can tell you the exact a/f ratio that the motor is currently at. So instead of just telling the ECU that the motor is running rich, it will read a voltage that correlates to an actual value, like 11.2. One thing to remember with a wideband sensor is that it has a heating element that needs to be heated up before the sensor will be accurate in its readings. This usually only takes a few seconds, but just remember that for those first few seconds the gauge is not useful. Wideband sensors give the ECU the ability to tune exact A/F value’s to a tenth of a decimal instead of just richening and leaning the mixture till a stoic value is seen.
What is Stoic, Rich, and Lean?
Stoic, rich, and lean are terms that we use to describe the burn ratio of fuel to air in the combustion chamber. The perfect ratio for good combustion of every fuel is called stoic. A stoic value will always give the motor a good clean burn while taking gas mileage into account as well.
Rich refers to conditions in the air fuel value were there is more fuel present than is ideal to the air content. Rich conditions will cause the burn to use more fuel, but can also offer more power at the same time.
Lean refers to conditions in the air fuel value were there is more air than fuel. This causes the combustion to occur rapidly and burn very hot. While this is great for gas mileage, often the vehicle will be down on power and become dangerous to the motors internals.