[jjohnny5]

Hey
E90 320i N46B20 2005
Once a while a big yellow check engine pops up on the dashboard. It
apperas after the car runs like it has no power for about 3sec. and after
the engine light turns on it seems to drive with full power.
Errors:

P0301 - Cylinder 1 Misfire Detected

P0303 - Cylinder 3 Misfire Detected

P0300 - Random / Multiple Misfire Detected Cylinder

P0040 - O2 Sensor SIgnals Swapped Bank 1 Sensor 1 / Bank 2 Sensor 1

Pops up mainly when accelerating, normally going to 2 thousand revs.
after that the car seems terribly slimy/slow and jerks for 2-3 sec. then
the check lights up, and above 3 thousand revs. the car accelarates
normally.
In addition, the car jerks and the idle is rough. Recently, the smell of exhaust fumes is being felt. The MPG is also
increased. This is mainly felt on a cold engine, sometimes on a warm one.
Valve sealants - new, spark plugs - new, coils- new,
Does anyone know whats going on with it?
Where can the exhaust gases in the cabin come from?
Thanks in advance for your help!

The car has no power. Can this be because of vanos/valvetronic?

Here are some INPA screenshots:

View post on imgur.com

[feuer]

Check if the o2 sensors are connected correctly. 2005 320i in US?

[jjohnny5]

Originally Posted by feuer

Check if the o2 sensors are connected correctly. 2005 320i in US?

Im in europe now. Thanks ill check it in like 1h

The lambda probes seem to be connected correctly

[jjohnny5]

Anyone?

[feuer]

Originally Posted by jjohnny5

Im in europe now. Thanks ill check it in like 1h

The lambda probes seem to be connected correctly

I'm from Europe myself and from memory I think N46B20 has two separate catalytic converters. Bank 1 for cylinder 1 and 4 and bank 2 for cylinder 2 and 3. Each catalytic converter has 2 lambda sensors, one before and another after the catalytic converter. The fault code your engine is showing is for this sensors being crossed/mixed installed, like o2 sensor for bank 1 installed on catalytic converter for bank 2. When I said check if they are installed correctly that is what I meant.

[jjohnny5]

It has to be something else. It seems like the cars PC is giving a bad gas mixture, and the o2 sensors are going crazy because of that.
The worst thing is that i have new coils and iridium spark plugs, i double checked them and they all seem fine.
I got a misfire on cyl 4 today with a new never before seen error. Inpa screens:

View post on imgur.com

[Thorin]

Swap those iridiums out for some factory BMW plugs.