[Danne335i]

Hi, as the title says im having some problems with my E92 335i 2008.
I have two codes and CEL on, 2CA7 and 2CAB. Took the car to my local shop they said it a bad o2 sensor, bank 2 pre cat, changed it for a new bosch sensor, error still came back.
Then i took the car to the BMW dealer, they basically said the same thing, but they wanted to put in another new sensor, which i let them but im still having the same codes and CEL.

Car runs fine, no misfires or anything, when i first got this error it was under normal driving(Was stage 2+ at the time).
This does leads to bank 2 fuel trims being way off and AFRs. Bank 2 is basically turned off, so i cant go in boost.
Checked many other threads with similiar codes, or same, that was solved by replacing the o2 sensor, my problem seems to be somthing else.

I have checked fuses, wiring, no cramped cables that i can see, so im asking here if anyone have any idea what it could be? Can the post cat o2 have effect on the pre cat o2, if its worth changing it aswell?

Any ideas is appriciated!

Car is modified(Stage 2+ when error first occoured)

Codes:
2CA7 - DME: Oxygen sensor heater 2 before catalytic converter: Function.
2CAB - DME: Oxygen sensor 2 before catalytic converter: Temperature.

[gbalthrop]

Originally Posted by Danne-E92-335i

...E92 335i 2008. I have two codes and CEL on, 2CA7 and 2CAB. Took the car to my local shop they said it a bad o2 sensor, bank 2 pre cat, changed it for a new bosch sensor, error still came back. Then i took the car to the BMW dealer, they basically said the same thing, but they wanted to put in another new sensor, which i let them but im still having the same codes and CEL. Car runs fine, no misfires or anything, when i first got this error it was under normal driving(Was stage 2+ at the time). This does leads to bank 2 fuel trims being way off and AFRs. Bank 2 is basically turned off, so i cant go in boost.
Codes:
2CA7 - DME: Oxygen sensor heater 2 before catalytic converter: Function.
2CAB - DME: Oxygen sensor 2 before catalytic converter: Temperature.

TWO OBSERVATIONS:
1) Avoid shops that believe that a fault code means replace "Part X" and do NO examination/testing of the associated electrical system.
2) Request money back from shop that repeated a prior R&R and achieved the same result: "Insanity."

Here is the TIS circuit diagram for the Lambda (O2) Sensors. Note the Orange wire from fuse F38 that supplies power to ALL O2 Sensor Heaters, including the Pre-cat Bank 2 sensor, B62201. Its "Installation Location" follows:
https://www.newtis.info/tisv2/a/en/e...ontrol/vF5QqMj
https://www.newtis.info/tisv2/a/en/e92-335i-cou/SHRnn4K

Note the "87" above the 30A Fuse Symbol for F38. That means that the fuse is powered only when Terminal 87 is active. When ignition is on, any Terminal 87 fuse should be powered. I would begin by locating BOTH Pre-cat O2 Sensor connectors, X62201 & X62101, and testing for 12V+ at the Orange wire, Pin #4, of each connector, particularly X62201 for Bank 2. Here are the Installation Location and Connector View for those connectors:
https://www.newtis.info/tisv2/a/en/e92-335i-cou/SCO2U5k
https://www.newtis.info/tisv2/a/en/e...i-cou/CT6giy7l

Also inspect the connector X62201, the sockets, pins & associated wiring, for any sign of damage, and clean the pins & sockets with electronic contact cleaner. Pin #3, White/Blue wire, at X62201 is JUST as important as Pin #4, in that it supplies the GROUND from the DME to activate the Heater.

Please let us know what you find,
George

[insanesam]

Originally Posted by Danne-E92-335i

Hi, as the title says im having some problems with my E92 335i 2008.
I have two codes and CEL on, 2CA7 and 2CAB. Took the car to my local shop they said it a bad o2 sensor, bank 2 pre cat, changed it for a new bosch sensor, error still came back.
Then i took the car to the BMW dealer, they basically said the same thing, but they wanted to put in another new sensor, which i let them but im still having the same codes and CEL.

Car runs fine, no misfires or anything, when i first got this error it was under normal driving(Was stage 2+ at the time).
This does leads to bank 2 fuel trims being way off and AFRs. Bank 2 is basically turned off, so i cant go in boost.
Checked many other threads with similiar codes, or same, that was solved by replacing the o2 sensor, my problem seems to be somthing else.

I have checked fuses, wiring, no cramped cables that i can see, so im asking here if anyone have any idea what it could be? Can the post cat o2 have effect on the pre cat o2, if its worth changing it aswell?

Any ideas is appriciated!

Codes:
2CA7 - DME: Oxygen sensor heater 2 before catalytic converter: Function.
2CAB - DME: Oxygen sensor 2 before catalytic converter: Temperature.

Hey mate

A while ago I had similar issues chasing O2 sensor codes (https://www.e90post.com/forums/showthread.php?t=1440250). Short answer was to replace the low pressure fuel sensor

[Danne335i]

Originally Posted by gbalthrop

TWO OBSERVATIONS:
1) Avoid shops that believe that a fault code means replace "Part X" and do NO examination/testing of the associated electrical system.
2) Request money back from shop that repeated a prior R&R and achieved the same result: "Insanity."

Here is the TIS circuit diagram for the Lambda (O2) Sensors. Note the Orange wire from fuse F38 that supplies power to ALL O2 Sensor Heaters, including the Pre-cat Bank 2 sensor, B62201. Its "Installation Location" follows:
https://www.newtis.info/tisv2/a/en/e...ontrol/vF5QqMj
https://www.newtis.info/tisv2/a/en/e92-335i-cou/SHRnn4K

Note the "87" above the 30A Fuse Symbol for F38. That means that the fuse is powered only when Terminal 87 is active. When ignition is on, any Terminal 87 fuse should be powered. I would begin by locating BOTH Pre-cat O2 Sensor connectors, X62201 & X62101, and testing for 12V+ at the Orange wire, Pin #4, of each connector, particularly X62201 for Bank 2. Here are the Installation Location and Connector View for those connectors:
https://www.newtis.info/tisv2/a/en/e92-335i-cou/SCO2U5k
https://www.newtis.info/tisv2/a/en/e...i-cou/CT6giy7l

Also inspect the connector X62201, the sockets, pins & associated wiring, for any sign of damage, and clean the pins & sockets with electronic contact cleaner. Pin #3, White/Blue wire, at X62201 is JUST as important as Pin #4, in that it supplies the GROUND from the DME to activate the Heater.

Please let us know what you find,
George

So i just followed your intructions gbalthrop and went ahead and checked The orange and Blue/White cable for both lambda sensors.
I do get +12v in both connectors bank 1 and bank 2.
In The Blue/White(ground) it is 4.33v in both connectors, bank 1 and bank 2.
Is the voltage in the ground pin too low? I followed the ground cable(Blue/White) to the DME and i was able to measure 12V. This was with ignition ON. With ignition off as you mentioned, there is 0v supplied.

2C9D - DME: oxygen sensor heater 2 before catalytic converter: Activation.
This code will show when disconnecting the harness instead of the other codes.

[jarots]

Originally Posted by gbalthrop

TWO OBSERVATIONS:
1) Avoid shops that believe that a fault code means replace "Part X" and do NO examination/testing of the associated electrical system.
2) Request money back from shop that repeated a prior R&R and achieved the same result: "Insanity."

Here is the TIS circuit diagram for the Lambda (O2) Sensors. Note the Orange wire from fuse F38 that supplies power to ALL O2 Sensor Heaters, including the Pre-cat Bank 2 sensor, B62201. Its "Installation Location" follows:
https://www.newtis.info/tisv2/a/en/e...ontrol/vF5QqMj
https://www.newtis.info/tisv2/a/en/e92-335i-cou/SHRnn4K

Note the "87" above the 30A Fuse Symbol for F38. That means that the fuse is powered only when Terminal 87 is active. When ignition is on, any Terminal 87 fuse should be powered. I would begin by locating BOTH Pre-cat O2 Sensor connectors, X62201 & X62101, and testing for 12V+ at the Orange wire, Pin #4, of each connector, particularly X62201 for Bank 2. Here are the Installation Location and Connector View for those connectors:
https://www.newtis.info/tisv2/a/en/e92-335i-cou/SCO2U5k
https://www.newtis.info/tisv2/a/en/e...i-cou/CT6giy7l

Also inspect the connector X62201, the sockets, pins & associated wiring, for any sign of damage, and clean the pins & sockets with electronic contact cleaner. Pin #3, White/Blue wire, at X62201 is JUST as important as Pin #4, in that it supplies the GROUND from the DME to activate the Heater.

Please let us know what you find,
George

+1

[gbalthrop]

Originally Posted by Danne-E92-335i

...
I do get +12v in both connectors bank 1 and bank 2.
In The Blue/White(ground) it is 4.33v in both connectors, bank 1 and bank 2...I followed the ground cable(Blue/White) to the DME and i was able to measure 12V. This was with ignition ON. With ignition off as you mentioned, there is 0v supplied.
2C9D - DME: oxygen sensor heater 2 before catalytic converter: Activation.
This code will show when disconnecting the harness instead of the other codes.

I realize we may have a bit of a language barrier here. You certainly understand my ONLY language better than I understand YOUR Native language.

There are two different issues to be dealt with here as I see it:

1) What is the proper DEFINITION of the three different codes you have listed? Related question: WHAT Scan Tool or software do you have available to read codes and their Definitions?
2) How exactly did you perform the tests for which you describe results? I can't understand why Pin #3 (White/Blue wire) voltage should be 4.33V rather than ~ 0V (in reference to Chassis Ground) or why BOTH Connectors should have the same voltage, when only ONE Sensor is setting Fault Codes.

I. Fault Codes & Definitions, Bentley listed FIRST, then BMW Fault Code Lookup:

A. 2CA7 (3 Different Definitions & P-codes):
P0059 | 2CA7 | H02S Heater Resistance (Bank 2 Sensor 1)
P0155 | 2CA7 | 02 Sensor Heater Circuit (Bank 2 Sensor 1)
P166F | 2CA7 | Internal Control Module Measurement Error 02 Sensor Heating (Bank 2 Sensor 1)

N54 P0155 2CA7 DME: Oxygen sensor heater 2 before catalytic converter: Function MSD80

B. 2CAB:
P166F | 2CAB | Internal Control Module Measurement Error 02 Sensor Heating (Bank 2 Sensor 1); NOTE: SAME Def as for 2CA7 above (3rd Def)

N54 | P166F | 2CAB | DME: Oxygen sensor 2 before catalytic converter: Temperature | MSD80

C. 2C9D:
P0050 | 2C9D | H02S Heater Control Circuit (Bank 2 Sensor 1)
P0051 | 2C9D | H02S Heater Control Circuit Low (Bank 2 Sensor 1)
P0052 | 2C9D | H02S Heater Control Circuit High (Bank 2 Sensor 1)

N54 | P0050 | 2C9D | DME: Oxygen sensor heater 2 before catalytic converter: Activation | MSD80 (ALSO P0051 & P0052, SAME Def.)

Regardless of which Definitions are applicable it appears that the Pre-cat O2 Sensor on Bank 2 (B62201 in Schematic) is NOT heating properly. That could be due to (1) an open circuit or intermittent 12V+ power supply from F38 via the Orange wire at Pin #4 of Connector X62201, (2) NO/Intermittent Ground supplied by the DME via the White/Blue wire at Pin #3 of X62201, or (3) a burned out or open resistor circuit in the Sensor (MOST UNLIKELY given that 3 different sensors have given same faults).

Unfortunately, there have been several reports of MSD80 failure resulting in lack of ground supplied to ONE of the two Pre-cat O2 Sensors. That is an internal DME fault and NOT a wiring or connector issue, so if you are NOT getting ground signal at Pin #3 (White/Blue wire) of Connector X62201, I would suggest doing BOTH of the following:
1) Test the other Pre-cat O2 Sensor Connector, X62101, for similar voltage at Pin #3 with ignition On.
2) Test at DME Connector X60002, Pins #12 & #13 for voltage in reference to chassis ground (with ignition ON).

If you are getting O2 Sensor Heater Fault codes ONLY for Bank 2 (NOT Bank 1 as well), then there MUST be a difference between pins in at least ONE of those tests above. If NOT, then either I don't understand something correctly, or my description of how to conduct the tests was NOT clear to you.

If you have either of the two (original & Bosch replacement #1 ;-) O2 sensors that shop & Dealer replaced, you can simply plug that into the connector and see if the heater works. Of course you can "bench-test" the O2 Sensor heater by applying 12V+ & Ground respectively to Pins #4 & #3. Assuming it heats when bench-tested but doesn't heat when connected to X62201, do the following tests at Connector X62201. Measure Voltage at Pin #4 (Orange wire), which should be 12V+ (with reference to Chassis Ground) with ignition on. Then measure voltage between Pin #3 (White/Blue wire) and Chassis Ground, also with ignition ON. That voltage should be ~ 0, as that needs to be a ground to have current flow through the heater element. I'm NOT sure of the BEST WAY to test a Control Module-supplied Ground, as you do NOT want to damage the DME by shorting the wrong thing to ground. Simply measuring voltage in reference to ground does NOT rule out an open circuit, so you might want to do a second test, measuring resistance, for "continuity to ground."

Here's the TIS circuit diagram for O2 Sensors again, showing the Connectors you tested, X62201 & X62101:
https://www.newtis.info/tisv2/a/en/e...ontrol/vF5QqMj

Please let me know if ANYTHING in the above is NOT clear/correct, conduct the voltage measurements again, testing as described above, and let us know the results.

George

[dpaul]

Originally Posted by gbalthrop

there have been several reports of MSD80 failure resulting in lack of ground supplied to ONE of the two Pre-cat O2 Sensors. That is an internal DME fault and NOT a wiring or connector issue,

I'm NOT sure of the BEST WAY to test a Control Module-supplied Ground, as you do NOT want to damage the DME by shorting the wrong thing to ground. Simply measuring voltage in reference to ground does NOT rule out an open circuit, so you might want to do a second test, measuring resistance, for "continuity to ground."

George

You may not be able to properly test a DME switched ground with a multimeter, at least by just making voltage measurements. For one thing, the heater circuit may not be constitutively active - i.e. is only on for a certain time period when the engine is actually started. For another, the DME may use PWM to regulate current flow. Furthermore, disconnecting the sensor may change the way the DME carries out activation of the circuit. Disclaimer, I don't know that MSD80/81s work this way but I know that other DMEs do.

I think the simplest test would be two part a) insure there is 12V, which the OP has already done, following your instructions. b) unplug the connector at the DME and measure resistance of the heater starting there - 2-5 ohms is typical. This directly tests both the heater and all of the wiring to it. I suspect that this will reveal both heater and wiring to be intact.

If there is heater voltage and the wiring is intact the only explanation is a bad DME. I had to replace the DME on my Jeep for the same reason. Of course that was much cheaper and simpler to do than this one will be.

[Danne335i]

Yes we might have a little language barrier indeed, this is not my native language but im gonna do my best to explain as best as i can.
I have not been able to work with the car today, but im planning tomorrow, but to clear some thing up(hopefully):

1. Im scanning the car with the MHD add, i dont have access to somthing else, might be able to use a more advanced scantool tomorrow and scan with.
2. When i was measuring Pin #4, key in inserted in the car, ignition ON, using a multimeter, one probe in connector X62201 Pin #4 and the other probe to chassis ground, this showed 12v or 11.9x to be exact. I did the same with connector X62101 Pin #4. Same thing with Pin #3, which oddly showed 4.31-4.33v in both X62101 and X62201.
I will do this test again tomorrow, i might have done the test wrong with Pin #3.
I double checked, my DME is MSD81 running IJE0S.

Hopefully i can get some more infomation on the codes with a "real" scantool tomorrow, Im gonna measure Pin #4 and Pin #3 in both connectors again, as i said i might have done it incorrectly.
Also gonna try to measure the resistance of the heater from the DME by unplugging it, as mentioned by dpaul and check Pin #12 and #13 at the DME.

I will get back with my results tomorrow, thanks for all the info!

[gbalthrop]

Originally Posted by dpaul

You may not be able to properly test a DME switched ground with a multimeter, at least by just making voltage measurements. For one thing, the heater circuit may not be constitutively active - i.e. is only on for a certain time period when the engine is actually started. For another, the DME may use PWM to regulate current flow. Furthermore, disconnecting the sensor may change the way the DME carries out activation of the circuit. Disclaimer, I don't know that MSD80/81s work this way but I know that other DMEs do.

I think the simplest test would be two part a) insure there is 12V, which the OP has already done, following your instructions. b) unplug the connector at the DME and measure resistance of the heater starting there - 2-5 ohms is typical. This directly tests both the heater and all of the wiring to it. I suspect that this will reveal both heater and wiring to be intact.

If there is heater voltage and the wiring is intact the only explanation is a bad DME. I had to replace the DME on my Jeep for the same reason. Of course that was much cheaper and simpler to do than this one will be.

Thanks for sharing that information. As you suggest, clearly there is 12V+ at Pins #4 (Orange wires) of BOTH Pre-cat sensor connectors, X62201 & X62101, and so (assuming sensor heater element is intact per your resistance numbers) we are looking at a bad connection between Pin #13 of X60002 at the DME and Pin #3 of X62201 (White/Blue wire), OR that DME-switched ground at pin #13 is bad. It would appear that devising a proper test to compare Pins #13 & #12 (Bank 1 Pre-cat Sensor Heater ground) at the DME would be the issue.

AFTER checking the integrity of the White/Blue wire between X62201 & X60002, to make sure it is neither open circuit, nor grounded, perhaps the following test? To rule out the possibility of disconnected sensor connector affecting DME function, it might be possible to "backprobe" Pins #13 & #12 at the DME and check voltage in reference to chassis ground during the minute after cold start, and COMPARE those voltage readings to determine if pin #13 is NOT providing a DME-switched ground? I know NOTHING about the actual Connector X60002 configuration at the DME, so can't say how difficult it might be to "backprobe" pins #13 & #12 of that connector.

I would NOT think, simply by looking at the TIS circuit diagram, that the DME is doing anything more than switching ground on/off at Pins #13 & #12. They are both connected to a "dumb" resistor or heating element in the Sensor, and my limited knowledge of electronics sees NO electronic component in the Sensor Heater circuit that would be controlled by a PWM (Pulse Width Modulated) signal from the DME. My SWAG is that it's an "all or nothing" switched ground. If that SWAG is correct, then if there is in fact a DME fault, there should be DIFFERENT Voltage comparing Pin #13 with Pin #12 in the backprobe test above, at least after cold start when Sensor Heater should be activated by DME.

Originally Posted by Danne-E92-335i

Yes we might have a little language barrier indeed, this is not my native language but im gonna do my best to explain as best as i can. [BOTH your use of English and technical knowledge appear "better than most" of US who just speak "Americanese."]
...
1. Im scanning the car with the MHD add, i dont have access to somthing else, might be able to use a more advanced scantool tomorrow and scan with.
2. When i was measuring Pin #4, key in inserted in the car, ignition ON, using a multimeter, one probe in connector X62201 Pin #4 and the other probe to chassis ground, this showed 12v or 11.9x to be exact. I did the same with connector X62101 Pin #4. Same thing with Pin #3, which oddly showed 4.31-4.33v in both X62101 and X62201.
I will do this test again tomorrow, i might have done the test wrong with Pin #3.
I double checked, my DME is MSD81 running IJE0S.

...I will get back with my results tomorrow, thanks for all the info!

NOT sure it really matters to get any more definitive "Code Definition" as unless I'm REALLY missing something, it appears to be down to proper DME-switched ground signal at Pin #3 of X62201 at cold start when O2 Sensor Heater should be activated.

As suggested by dpaul (and "theorized upon" by me above ;-), the trick is to devise a test to compare "ground signals" at Pins #13 & #12 of X60002 to determine if #12 works & #13 does NOT. Here are the TIS "Installation Location" and "Connector View" for X60002 in the E-box:
https://www.newtis.info/tisv2/a/en/e...cou/1VnZAHHjcD
https://www.newtis.info/tisv2/a/en/e...i-cou/CTItv0r3

Have you EVER had to replace F38, the fuse that powers the O2 Sensor Heaters? Any repairs or replacements under the hood just before this issue began?

ANYONE know what electronic component in the DME switches that ground (transistor, etc.), and what the likelihood of a shop being able to repair that for ~ $100 US might be?

Please let us know what you find so we can all learn something from your experience.

George

[Danne335i]

Originally Posted by gbalthrop

Have you EVER had to replace F38, the fuse that powers the O2 Sensor Heaters? Any repairs or replacements under the hood just before this issue began?

George

I have never replaced the F38 fuse(any fuse during my 5 years of ownership) the only job i did under the hood before this was installing DCI's, i cant say for sure how long after the installtion it took for the codes to show up, approximately 2-3 weeks, other than that, no major jobs or repairs under the hood before this issue.

[dpaul]

Originally Posted by gbalthrop

I would NOT think, simply by looking at the TIS circuit diagram, that the DME is doing anything more than switching ground on/off at Pins #13 & #12. They are both connected to a "dumb" resistor or heating element in the Sensor, and my limited knowledge of electronics sees NO electronic component in the Sensor Heater circuit that would be controlled by a PWM (Pulse Width Modulated) signal from the DME. My SWAG is that it's an "all or nothing" switched ground. If that SWAG is correct, then if there is in fact a DME fault, there should be DIFFERENT Voltage comparing Pin #13 with Pin #12 in the backprobe test above, at least after cold start when Sensor Heater should be activated by DME.

George

Not sure what SWAG means but willing to make a (small) bet that:
1) you can't tell anything serious about the actual DME circuitry from the TIS diagram. It's great for pin outs
2) you won't get any useful measurement about the status of the ground switching without having the engine running.
3) you'll see evidence of PWM if you backpinned and scoped the heater return to the DME (if the DME was functioning correctly). I have done this although not with an MSD80/81.

[gbalthrop]

Originally Posted by dpaul

Not sure what SWAG means...

SWAG:

1. Scientific Wild Ass Guess
2. Stupid Wild Ass Guess

Applicable meaning based upon context -- in my case, choose (2).

[dpaul]

Got it! Well, we have now exchanged SWAGs!

[Danne335i]

So today ive managed to test some more and here is what i came up with:
I have tested both connectors, X62101(Bank 1) and X62201(Bank 2).
Also checked some live data.

With ignition OFF:
X62101(Bank 1) - Pin #4 Is showing 0v. Pin #3 Is showing 4.33v
X62201(Bank 2) - Pin #4 Is showing 0v. Pin #3 Is showing 4.33v

With ignition ON:
X62101(Bank 1) - Pin #4 Is showing 12v~. Pin #3 Is showing 4.33v
X62201(Bank 2) - Pin #4 Is showing 12v~. Pin #3 Is showing 4.33v

Also did the following on BOTH X62101(Bank 1) and X62201(Bank 2):
Testing Pin #3 when starting the engine, voltage drops to 0v and then pulses between 0v and 4v. Tested with the connector apart.

Also checked the post-cat o2s with some live data:
Post-cat o2, bank1, working between 0.1v and 0.9 adjusting quite alot.
Post-cat o2, bank 2, keeps sitting still at 0.855 and 0.9.(Maxed out?)
Not sure if this has anything to do with my problem but, though i might point it out, bank 2 post-cat maybe doing this because of pre-cat o2 failure?
Tests were done exactly like previously, one probe in the correct pin and the other to chassis ground.

[dpaul]

Neither post-cat read out is what you'd hope. Should have steady reads, normally 500-700mv. So your bank 2 is reading constitutively rich. Bank 1 fluctuation is potentially worrisome. Fluctuation is what you'd generally see on the pre-cat wide-band sensors, as the DME flips the mixture between rich and lean conditions. Post cat it should be steady if the cat is working. Simplest explanation of fluctuating output on a post-cat sensor is that the cat converter itself is dead or dying.

But before thinking too much about that, lets go back to your initial problem. It seems likely there is nothing wrong with your pre-cat sensor wiring and given that you've replaced the sensor itself, likely that there is nothing wrong with it either.

On the other hand, both of your codes have a common interpretation of "Internal Control Module Measurement Error". The simplest interpretation of that is a faulty DME. That might be uncommon for the MSD80/81. Maybe someone can come up with another reasonable explanation.

[Danne335i]

Originally Posted by dpaul

Neither post-cat read out is what you'd hope. Should have steady reads, normally 500-700mv. So your bank 2 is reading constitutively rich. Bank 1 fluctuation is potentially worrisome. Fluctuation is what you'd generally see on the pre-cat wide-band sensors, as the DME flips the mixture between rich and lean conditions. Post cat it should be steady if the cat is working. Simplest explanation of fluctuating output on a post-cat sensor is that the cat converter itself is dead or dying.

I have catless downpipes, might explain why, but they still dont read the same.
But it still wont help me with my previous problem :/

[dpaul]

Cat removal explains the fipping on bank 1. Bank 2 high voltage may also make sense in light of the description in your first post that your trims are maxed on bank 2 (to the extent that you don't have boost?). Presumably, the DME cannot properly read the AFR for Bank 2 and is running open loop.

Again, the only explanation I can make for your continued problems is a faulty DME sensor heater driver.

[Danne335i]

Originally Posted by dpaul

Cat removal explains the fipping on bank 1. Bank 2 high voltage may also make sense in light of the description in your first post that your trims are maxed on bank 2 (to the extent that you don't have boost?). Presumably, the DME cannot properly read the AFR for Bank 2 and is running open loop.

Again, the only explanation I can make for your continued problems is a faulty DME sensor heater driver.

Ah thats what i thought. If i got this right, my fuel trims are not maxed out(Short term fuel trims, STFT) Bank 2 sits at 0.0, AFRs are high when monitoring though MHD, bank 1 is working fine, by looking at logs.
Gonna have the car checked out next week, someone with more knowledge than i have and the right tools, hopefully its not the DME..

[dpaul]

Suspicious for fuel trim to sit at 0.0

Post your log in datazap.me

This what you said earlier “This does leads to bank 2 fuel trims being way off and AFRs. Bank 2 is basically turned off, so i cant go in boost.”

Not at all sure what you mean in second sentence

[Danne335i]

Originally Posted by dpaul

Suspicious for fuel trim to sit at 0.0

Post your log in datazap.me

This what you said earlier “This does leads to bank 2 fuel trims being way off and AFRs. Bank 2 is basically turned off, so i cant go in boost.”

Not at all sure what you mean in second sentence

I meant not to push the car, going WOT, should have gone into more detail typing that, sorry.
This log is from a custom base map that im currently running, not pushing any big power, since the car has new turbos and fuel system added to it.....Never though theese codes would cause this much problems, should obviously have sorted it out first, but here i am.

https://datazap.me/u/dannee92/log-15...og=0&data=3-21

Edit: Resetting adaptions for lambda regulation and sensors via mhd, will cause stft 2 and bank 2 AFRs to drop to normal levels, matching bank 1, for like 2 minutes, then again stft 2 gets stuck at 0.0 and AFR for bank 2 will climb.

[dpaul]

I'd be worried about driving the car in this condition.

Obviously, the DME is getting no useful information about bank 2 AFRs. You post-cat reading suggests it is running bank 2 excessively rich but who knows what is actually going on. Crazy throttle closings. Some timing pulls although not crazy bad. As you already know, you should go back to stock tune for trouble shooting.

[wei888]

Danne, or anyone who may have the answer.
Any final updates for the car with 2CA7?
I'm have the exact same issue on my 2008 528i. Zero on STFT B1S1. I replaced the o2 sensor on B1S1. Code didn't go away 2CA6.
Will be great if your car is fixed. Please let me know.