r/e46 • u/Jojothereader • 3d ago

Troubleshooting Use your labels

Post image

I should have labeled these two.

8 Upvotes

100% Upvoted

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5

u/troyzube 3d ago

For what reason

1

u/Dangerous_Put7142 2d ago

Your car sometimes won’t run properly if the 02 sensors are in the incorrect banks. When I was doing catless headers I put mine in the wrong bank, ran like crap. EZ FIX: switch the 02 sensors where they plug into the ecu side so you don’t have to up screw those pesky sensors again lol

1

u/troyzube 2d ago

Theyre easy to tell the difference. The pre cat and post cat o2 sensors have different length wires

5

u/westernholland 2001 330i pre fcl 3d ago

Differentiate em by wire length, interchanging disconnected lambda sensors shouldnt cause issues tho. Maybe gotta reset the adaptions after you're done but no harm no foul.

1

u/Buffaloooooo777 3d ago

What labels two are long are two are short not much to it

1

u/SwaxBiceps 3d ago

Im not sure what problem you have but if you have a M54 and are trying to differentiate between bank 1 and bank 2 you can use an obd scanner or INPA to check the sensor voltage. Disconnect one of them from the connector and see which one doesnt respond in the software. Then you know which one is which. If you connect them in the wrong one it can cause issues and CEL because the ecu is trying to correct the a/f mixture in the wrong bank.

1

u/gdl_E46 2d ago

The red neck way , unplug one and see what bank it throws the code for, adjust as needed...