VRSF Catless Downpipes and codes 2CA6 2CAA

JasonWeise

New Member
Jan 12, 2022
5
2
0
Gold Coast - Australia
Ride
E90 335i & E87 130 M-Sport
Hi community

I have recently had VRSF Catless Downpipes installed on E90 335i and am seeing 2CA6 and 2CAA codes which seem to one point to pre and post cat heating for Bank 1.

I use MDH tune (kept to stage 1 for now to be safe) and have run reset all calibrations but cannot get rid of these codes. These are in fact the only codes I am seeing and the car runs beautifully.

My biggest concern is AFR's and I think it might be from the codes I am seeing - Running logs from MHD I am seeing on boost the following results:
At 12.8 PSI
Bank 1 - Lambda ~17.8
Bank 1 - STFT 0
Bank 2 - Lambda ~12.1
Bank 2 - STFT -12

Bank 1 seems wayyy to lean but I don't know if this is a false reading due to 2CA6 and 2CAA error codes. Is it possible secondary O2 sensors being around the wrong way would cause this? The reason I ask is I am amost positive secondary O2 was grey in bank 1 when I looked under the car on the weekend and I thought BANK 1 was black for primary and secondary O2.

Before I get the car up on ramps again just thought I would check with the community here to get thoughts on 2CA6 and 2CAA as these just don't seem to want to go away and if they are not typically caused by secondary O2 issues I will start my troubleshoot elsewhere.

NOTE: I have catless DP check on MHD but do still have a hollow yellow engine check light - as said no other error codes besides these :)
 

SLOWESTN54

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Feb 9, 2021
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2007 E92 335i / 2008 E60 535i
Bank one should be a black, Bank 2 should be grey. I'm guessing your pre cat bank 1 O2 needs to be replaced.

EDIT: i may be wrong but you can't plug in post cast o2's backwards, it would have to be the wrong sensor in the wrong downpipe. Also theirs's a specific code for when the post cat O2's are backwards.
 
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JasonWeise

New Member
Jan 12, 2022
5
2
0
Gold Coast - Australia
Ride
E90 335i & E87 130 M-Sport
Bank one should be a black, Bank 2 should be grey. I'm guessing your pre cat bank 1 O2 needs to be replaced.

EDIT: i may be wrong but you can't plug in post cast o2's backwards, it would have to be the wrong sensor in the wrong downpipe.
Thanks for the speedy reply.

Yeah I didn't think they could be connected wrong after reading about a million threads. I had a shop install the downpipes so maybe they put them in the wrong way around. I am going to have to get off my lazy bum and put the car back up an ramps I think just to double check.

Do you think having the post cat (secondary) O2's around the wrong way would cause 2CA6 and 2CAA. One of those codes are for pre-cat bank1 and the other post cat bank1 I think. Just seems odd both codes are complaining about bank 1 O2's (both of them).

I could be interpreting the codes wrong - I come from a JDM background and found the light into Euro's (matured with age I guess) :joycat:
 

SLOWESTN54

Lieutenant
Feb 9, 2021
738
477
0
22
B.C. Canada
Ride
2007 E92 335i / 2008 E60 535i
Thanks for the speedy reply.

Yeah I didn't think they could be connected wrong after reading about a million threads. I had a shop install the downpipes so maybe they put them in the wrong way around. I am going to have to get off my lazy bum and put the car back up an ramps I think just to double check.

Do you think having the post cat (secondary) O2's around the wrong way would cause 2CA6 and 2CAA. One of those codes are for pre-cat bank1 and the other post cat bank1 I think. Just seems odd both codes are complaining about bank 1 O2's (both of them).

I could be interpreting the codes wrong - I come from a JDM background and found the light into Euro's (matured with age I guess) :joycat:
The downpipe closest to the trans will be bank one just double check to make sure its black. From what I've seen its highly likely you just have a bad pre Cat 02. If you could post a log that also greatly helps.
 

carabuser

Lieutenant
Oct 2, 2019
548
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UK
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Z4 35i & 335i
O2 Sensor Locations.jpg


I found this on a forum somewhere. This is what I used when doing the job.
 
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JasonWeise

New Member
Jan 12, 2022
5
2
0
Gold Coast - Australia
Ride
E90 335i & E87 130 M-Sport
Thanks for everyone's help so far, so now I have more confusion than before.
I got the car up on ramps and had a look at the secondary O2 positions and have confirmed that the secondary O2 in Bank 1 is definetly grey wire and Bank 2 is definitely black wire.

Problem is, this is reversed at the primary O2's, the Bank 1 O2 wire is black and the Bank 2 O2 wire is grey :confused: - certainly as far as I can see (included photos below)

Here are some photos of the secondary O2's and I had come to the conclusion that the installer got the secondary O2's around the wrong way - but - you couldn't get them wrong, the grey secondary O2 sensor wire doesn't appear to be long enough to "accidently" get them around the wrong way - in fact it looks like they are still perfectly attached to their fixtures.

Note: As a test I did try and swap the primary O2's around by swapping the plugs as they are not keyed and the MHD showed error "O2 positions swapped" so I am thinking the primaries must be right (but I am now confused so who knows LOL)

I guess my question is - why LOL,
Bank 1 Primary O2 - Black Wire
Bank 1 Secondary O2 - Grey Wire

Bank 2 Primary O2 - Grey Wire
Bank 2 Secondary O2 - Black Wire

IMG_1257b.JPEG


IMG_1254b.JPEG


IMG_1267b.jpeg
 

SLOWESTN54

Lieutenant
Feb 9, 2021
738
477
0
22
B.C. Canada
Ride
2007 E92 335i / 2008 E60 535i
Bank one should be black and bank 2 should be grey. Your secondaries are backwards. If you put the Bank one O2 part number into Fcp euro it’s a black wire.
 

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JasonWeise

New Member
Jan 12, 2022
5
2
0
Gold Coast - Australia
Ride
E90 335i & E87 130 M-Sport
Hey @SLOWESTN54 you are sooo fast at giving help.. thanks heaps.

From all the images and forums posts I have seen that seems to be right, they are back to front but the actual O2 wires don't seem to be long enough (at least the grey one) to be the wrong way around.

If I changed them, the black one looks as if it would hang too long and the grey seems it wouldn't quite reach LOL.

Do you think they have been pulled all the way out by the installer and it just "looks" like the length is wrong?
 

SLOWESTN54

Lieutenant
Feb 9, 2021
738
477
0
22
B.C. Canada
Ride
2007 E92 335i / 2008 E60 535i
Hey @SLOWESTN54 you are sooo fast at giving help.. thanks heaps.

From all the images and forums posts I have seen that seems to be right, they are back to front but the actual O2 wires don't seem to be long enough (at least the grey one) to be the wrong way around.

If I changed them, the black one looks as if it would hang too long and the grey seems it wouldn't quite reach LOL.

Do you think they have been pulled all the way out by the installer and it just "looks" like the length is wrong?
No worries, if I have a minute I’ll always go through my notifications. The black wire you’ll have some extra. And the grey will be a little tight but it all should fit.