Could a bed O2 sensor to cause misfire and always shutdown the same cylinder (4 for right side or 1 for left side)

The car is S320 W220 MY2000 112.944 3.2L V6 engine.

History:
Few month ago I got P170/173 code, change the MAF twice, first was not OEM.
Now there is no P173/170 but after second MAF I got some misfires code P300/301/302/304 and O2 code P0130/150 right/left before KAT, I reset them all.
Meanwhile I replace also the sparks, and the idle is much better.
Under kickdown is doing a misfire and now only on cylinder 4, I have swap the ignition coil between 4 and 1 and the misfire is still on 4.

 

Hi,
It appears that you now have a "good" scanner.
P0130/P0150 are O2 circuiut malfunctions. Arte you sure the O2 sensors are connected and these codes aren't historical from when you may have started the car with the sensors were disconnected.
Clear codes. Do they come back?


What do the O2 sensor outputs look like on your scanner?
Are the sensors cycling correctly?

If not the O2 sensors or wiring must be faulty.

If the O2 sensors aren't working correctly the fuelling will be incorrect.
Sometimes one cylinder may be more sensitive than others to misfire due to manifold design and tolerances on the injector etc.

I DO NOT think it will help but have you changed the injector for a one from a different cylinder? Likewise the plug lead as well as the coil pack.

You will recall that I stated that the O2 sensor operation should be checked BEFORE changing the MAF a second time..
The MAF is only one input to the ECU.
There are of course many other inputs including the O2 sensor.

Hope this helps.

Stuart

 

The P130 come back after one week and reset again, 3-4 weeks from then and no code but the symptoms: misfire under heavy acceleration.
I don't have a data logger but looking to instant values was quite clear that right side is different then left side.
If I will change the right side should I change them both side or even the after cat ones?
What is the role of the second sensor, theafter cat sensor?
Thanks again for help.

 

Sensors are quite expensive so its how much you wish to spend on Prevention!
If a sensor is working, it is working although it may be somewhat sluggish etc.
The issue is when might it fail. O2 sensors don't last last forever so you need to know if it been changed since new. When will it fail etc. Your guess is as good as mine.
Biggest cause of failure is contamination. Here in the UK there has been a major problem with "contaminated" petrol where an anti foaming agent for Diesel was inadvertently added and got through specification checks. sensors didn't fail immediately but the pattern quickly became apparent and thousnads of cars suddenly started appearing on tow trucks etc. There weren't enough O2 sensors available in the world to resolve the problem and some customers were without their cars for several days.

Changing sensor left to right will serve to confirm your diagnosis but if the sensor output is not cycling correctly it is likely that the sensor has gone bad.

The second sensors are there in order to apply the greatest possible level of control over combustion. The second sensor ensures how effective the first cat system has been (effectiveness reduces over time whereas the legislative requirement doesn't!) and if necessary takes action to further clean the exhaust with additional egr 9exhaust gas recycle) etc to "dilute" the emmissions content to within legislative requirements. USE OF EXCESSIVE EGR HAS IMPACT ON DRIVEABILITY, POWERETC. Oops Capitals.

Two sensors tend to be used only in countries with stringent emmissioin requiurements eg. California.

Stuart

 

May I suggest a replacement for Oxygen sensors?

http://www.ngkpromotions.com/product...sors/index.asp

Check it out.....

Rockerfella174

Brunei Darussalam

 

Today I have been at the dealer for anual road check and change both O2 sensors.
The problem with shuting down cylinder 4 over ~5k rev. is still present.
But the fuel economy(board computer read out) is again better then ever so that's good.
The diagnosis is now with the dealer, I will visit him again next week and he will swap the injectors first and then we will see.

 

Finally the engine is repaired.
Seems that the problem was cause by a soak connector, they cleaned and voila running like new: kick-down up to 6000 rev with full power.
As for the engine light is turn off from the system, probably due to many false alarm would give.