M3 02 sensors - wideband?

[DaRk_AnGeL]

Yesterday I was told that my M3 (3.2 USA spec) which needs new lambda (O2) sensors, can use wide-band (if I am writing it correct) sensors and perform better. Just to mention that I live in Europe (Greece) and my engine (M3 3.2 USA spec) and ecu are designed to work in accordance with USA fuel where (if I remember correct) octanes are less. In Greece, simple unleaded has 95 octanes and the other qualities range from 97 to 100.
So, what I was actually been told, is that if I replace my O2 sensors with wide-band, I will get better performance, coming from the more efficient fuel use. In technical terms...can this be true? Is it worth trying it or is just nonsense?
:dunno:

[BeRzErKaS]

YES, a wideband 02 sensor will provide a more accurate air/fuel reading and the use of one MAY result in better fuel economy if someone uses the wideband data to retune your fuel map.

NO, you can not directly install a wideband sensor in place of your stock narrow band sensor and expect it to work with your ECU. The two sensors operate under two different voltage ranges.

The stock sensor operates in the "narrow band" between 0-1V and the wideband senor operates in the much "wider band" between 0-5V. The increased bandwith allows for better signal resolution which is the reason wideband sensor readings are more accurate and better for tuning.


You have two options:

Drill and tap your exhaust pipe then install the wideband sensor IN ADDITION to the stock sensor. Leaving the stock sensor in place will keep the ECU happy and keep the CEL from popping up.

- Or -

Remove the stock sensor completely and install the wideband sensor in its place. In order for this to work you will have to choose a wideband kit that comes with an electronic module that sends a "simulated narrowband signal" to the ECU to keep it happy. This is the route I chose. I have the Zeitronix wideband kit.


Either way, you still have to take your car to a knowlegable technician who knows how to use the wideband data to properly and SAFELY retune the car.

[DaRk_AnGeL]

YES, a wideband 02 sensor will provide a more accurate air/fuel reading and the use of one MAY result in better fuel economy if someone uses the wideband data to retune your fuel map.

For the moment my engine has almost no tunnings.. so, by changing all four sensors with wideband, all that is expected as a gain is better fuel consumption?

YES
Remove the stock sensor completely and install the wideband sensor in its place. In order for this to work you will have to choose a wideband kit that comes with an electronic module that sends a "simulated narrowband signal" to the ECU to keep it happy. This is the route I chose. I have the Zeitronix wideband kit.


That seems much more sensible to me... so, suppose that I change all four sensors, and use a wideband-kit, this will send to ECU the "simulated narrowband signal". Will this be enough for the ECU or the need for remapping will be needed immediately?
Meaning... with this setup the engine will just be able to function as before, will it perform better or it will be on hold for chip or remapping or whatever?

[BeRzErKaS]

So you mention that you have 4 oxygen sensors? So you must have the newer model e36.

My '94 325is is OBD1 and has only one oxygen sensor from the factory. That's why the sensor swap with simulated narrowband output worked well for my application.

With 4 sensors your setup would be different. Don't buy 4 wideband sensors. Truthfully, the first option may work best for your application. Just have an exhaust shop drill and weld a socket on the collector pipe of the exhaust manifold and install the wideband there. Leave all the rest of your sensors in place.

If you were to purchase a good quality wideband kit with a fast sampling rate and a proper conversion factor for simulating the narrowband output then the car should behave just as it did before. The sensor is just a tool for collecting information. The ECU is what processes the information and adjusts the engine characteristics. You would need a retune to see the real benefits.

The only real benefit to a wideband sensor conversion is more accurate tuning capability which is important for cars with extensive engine modifications or superchargers or turbochargers.

A wideband sensor conversion is not a common modification for a relatively stock car.

[DaRk_AnGeL]

To give you a better picture of my car.... It is a 3.2 M3 (usa spec), conversion from 316i. The point is that I bought the car like this, and during the conversion, only two lambda were used, the ones on the exhaust manifold. The other two, which were supposed to be placed after the catalytic converters... are absent.
So, I am thinking first of all to restore the two missing ones, and give the ECU a chance to collect all data needed, and then replace the ones present with new to see if I get rid of some temporary losses in power I face from time to time. My mechanic told me that this may be a solution to my problems (along with the new bremi kit I am expecting these days).
So... given those data, would you still suggest that I use the ones that the factory uses and an extra one (or maybe two - one on manifold and one after catalysts) to enrich the collected data? Or maybe something else ??