There should be a sensor number to go with it to identify if pre or post cat.
E46 02 sensors.
Your post cat oxygen sensors are there only to check if your catalytic converters are working correctly.
A faulty oxygen sensor a relatively small component of the fuel delivery system can have a large impact on fuel economy and engine performance in the bmw.
Bank 1 identifies the front bank of engine.
Only 6 left in stock order soon.
A bad or failing oxygen sensor will have a negative impact on environmental emissions and engine performance so there are a 3 things to watch out for before your oxygen sensor completely fails.
There are two types of engines inline engines and transverse engines engines that are mounted in other directions.
For the bmw 3 e46 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 model year.
December 16 2017.
If you know which cylinder is 1 it wouldn t matter anymore whether your engine is transverse or inline as bank 1 will always be on the cylinder marked 1 3 5 7 9 11 and bank 2 will always be on the side of the cylinder marked 2 4 6 8 10 12.
Every 20 miles the dme will but the the engine through a test cycle where the afr is altered and the dme will wait for the post cat o2 sensors to pick up the change in o2 concentration.
Check engine light comes on.
Is that the upstream sensor.
Sangyue 02 o2 oxygen sensors for bmw e46 323i 325ci 325i 325xi 328i 330ci 330xi 330i upstream downstream 4pcs.
Followup from the pelican staff.
Nick at pelican parts.
An observant driver will take heed of its symptoms and address the issue before the malfunction becomes a full replacement.
The oxygen sensor transmits the data to the vehicle s pcm to maintain the optimal air to fuel ratio for your engine.
Sangyue 02 o2 oxygen sensors for bmw e46 323i 325ci 325i 325xi 328i 330ci 330xi 330i upstream downstream 4pcs.
Only 5 left in stock order soon.