X5 diesel engine noise - With VID.

[Dr. Anthony]

Originally Posted by bawareca

I didnt hear anyone here replacing the NOX sensor. And why will both (?) fail at once?

Originally Posted by ard

In air leak can cause odd noised under various running conditions as air if forced through a orifice (think wind instruments) ...AND...unmetered air entering the engine can ALSO cause the DDE to think you are getting erroneous NOX readings and trip codes.

I would NEVER think a code that says "nox sensor" means unequivocally that the nox sensor is bad. Never. Good guess perhaps, but not the only thing that can trip codes.

my 2 cents

You're absolutely right. I've run out of ideas so before it gets too crazy, I'm going to have a friend's indy shop take a look at it for me this afternoon.

Also, the code (3 codes) are all referring to the name nox sensor.

they are:

46B4: NOX Sensor before denox cat plausability nox.
4BB3: Nox sensor before denox cat- plausibility nox
4b6a: Nox sensor before denox cat - Plausibility

to me, I'm reading it as the nox sensor before the cat has died.