C200 Kompressor 2007 W204

HEllo guys hope you are doing well

I have a question, I have a C200 Kompressor 2007 W204 and a scantool Xentry diagnosis and i wanted to test my mixture using the o2 sensor signal and this what i found that i cannot understand ( picture attached).. I was at idle.. i watched couple of videos on paul's channel where he said that the o2 sensor signal fluctuate between arround 800mv and 150mv depends on the lean/rich condition.

But in this picture attached, i don' t have fluctuation between this range, also the voltage shown is arround 1.1 v fixed..

I do not have check engine, everything looks good in my scan tool, even these o2 sensor values are in the range ( because in this scantool it shows me the range that this o2 should be at idle..

Anyone can explain for me this picture guys :

I apreciate your help

sorry i did not mention that it is Euro version car

The upstream sensor on your car is not the conventional O2 sensor. Your car features a wideband A/F ratio sensor. This sensor's activity is actually measured in miliamps and the scandata is only an interpretation by the ecm. It is normal to see pretty stable readings on the scanner, you will see minor variations during heavy acceleration/decelaration. Nothing to worry about there.

The downside sensor is a conventional style sensor. With a working catatlytic converter you will get an almost fixed voltage reading here as well. This indicates that the catalist is doing his job efficiently. Again, on full throttle acceleration and decearation you will spot some activity.

Juergen nailed it. Those values look fantastic.

Take it for a WOT ride and take note of what the same sensor does during power enrichment and fuel cut decel. That'll give you a better idea of how these sensors operate.

Thank you very much for your kind help I am happy to be here to get some information

Just i have a question, I know that the conventional O2 signal will rise at rich condition and will drop at lean condition.. but with A/f ratio sensor what are the values for rich and lean condition?

Do you know a good video that can explain for me all these stuff?

Thank you man!! I apreciate your help

samikhazaal wrote: Just i have a question, I know that the conventional O2 signal will rise at rich condition and will drop at lean condition.. but with A/f ratio sensor what are the values for rich and lean condition?

Generally speaking, you'll see the sensor reading drop below the stoichiometric value during a rich condition, and higher during a lean condition. Stoich, in your case, is that 2.00V reading you saw. What the exact values will be depends on the sensor and the vehicle application.

Like I said, a WOT drive will show you both extremes. For fun, you can also generate a dead misfire (disconnect a coil/injector) and observe how the sensor reading and the lambda adjustment changes.

Do you know a good video that can explain for me all these stuff?

Not right off hand. We have a thread started about air/fuel sensors in general, but I haven't had the opportunity to experiment with MB.

www.scannerdanner.com/forum/diagnostic-t...-testing-thread.html

samikhazaal wrote:
Do you know a good video that can explain for me all these stuff?

This is the first part of a mini serie:



Different makes have different baselines....good A/F sensor readings at idle I Know/use are:

Honda 2.8V
Toyota 3.3V
Nissan 1.4V
Hyundai 1.9V
Subaru 2.4V

The Lambda PID is a useful tool in analyzing the mixture : It should stay really clos to 1.00.

Thanks for those numbers. I was thinking the other day that it would be cool to have a thread with known good values for different set ups.

The more recent Nissans now have a lamda of 2.2v. I can't remember when it changed, but it has been a while, so I just know to look for 1.5v or 2.2v.

Nissan Technician

Guys thank you very much for your help !!