02 Sensors - Replace now?

[happos2]

Maybe I will get some more help in this forum:

MY 03/08 E92 M with pullies / test pipes / air filter / Stage II tune.

I had issues with my Throttle Valve Actuators and got them replaced under warranty (though had to pay a deductible). Now I have some O2 sensor faults (known to be problematic sometimes) so I just want some help deciphering which ones I need to replace. Here are the codes:

27C7 - Lambda sensor trim control AD diagnostic bank 2
2771 - Lambda sensor dynamic diagnostic VKAT bank 1

From my understanding:
VKAT = VOR (before) Cat
NKAT = NACH (after) Cat
bank 2 = drivers side
bank 1 = passenger side

Originally Posted by Sam@Alekshop

2771 - P0133
Information saved in: DME
Fault code: 2771 - P0133
Fault text: Oxygen sensor dynamic diagnosis before catalytic
converter, bank 1
Fault description: O2 Sensor Circuit Slow Response (Bank 1 Sensor
1)

Condition for fault identification
Test condition: Amplitude of oxygen sensor less than diag. value
0.35 (K_LAVK_OBD_DYN_WERT_MAX)
Terminal condition: Engine running - Condition idle or partload
Voltage condition: none

Condition for fault memory entry: none

Action in service:
1. Clear fault memory, oxygen sensor system test
2. Check exhaust system for leaks
3. Replace pre-cat oxygen sensor LSVK B1

Fault effect and breakdown warning: MIL on after engine runs 2x /
possible mild effect on drivability...surge during steady-state
operation

Driver information Warning light: MIL

Service instruction: none

=====

27C7 - P2099
Information saved in: DME
Fault code: 27C7 - P2099
Fault text: Oxygen sensor, adaptation, trim control, bank 2
Fault description: Post Catalyst Fuel Trim System Too Rich (Bank
2)

Condition for fault identification
Test condition: Adaptation value reaches max. limit and hangs in
this position
Terminal condition: Engine running
Voltage condition: none

Condition for fault memory entry: Counter for recognition at
adaptation limit >= (2x) K_LA_TRIM_DIAG_I_AD_MAX_SCHW

Action in service:
1. Check the fuel system and the exhaust system for leaks
2. Check pre-cat and post-cat sensors and replace as indicated

Fault effect and breakdown warning: MIL on after engine runs 2x

Driver information Warning light: MIL

Service instruction: none

First I should check for leaks, and if that doesn't fix it (which I don't think it will as I had this code when my Throttle Valve actuator went but was replacing that first to see if it cause erroraneous signals), then I should replace both Pre-Cat O2 Sensors. Just want some concurence prior to buying the following O2 sensors:

http://www.amazon.com/Bosch-17039-Ox.../dp/B000JZEXG8

Thanks for the reassurance!

[happos2]

Anybody?

[elm3]

If it is throwing those codes, I would replace the O2 sensors. It looks like both banks are faulty. Most likely the pre-cat ones.

[happos2]

thanks! I am pretty sure this is what I am going to do!