P0175 Bank 2 System Rich Code

e code · 09-30-2021, 03:25 PM

Hey all, I have searched for info on my issue forwards backwards and sideways. I have been trying to diagnose this code for the better part of a year now. The code is intermittent but lately the CEL has stayed on.

No real symptoms other than a slightly lower than usual idle, talking like maybe 50 rpms off. Gas mileage is fine currently averaging 22.5mpg. Still pulls like a freight train. It's on a mission tuning stage one tune FYI.

Heres what I have tried:

I put a smoker on it and no leaks from either bank.

I cleaned the MAFs and cleared the code like 8 months ago. The code didnt come back for a couple months of daily driving. Figured it was a dirty MAF or it needed to be replaced. The code came back but its only bank 2 so I figured if its the MAF then if I swap one side for another then the code would switch to bank 1 giving me a P0172. So I swapped sides with the MAFs, cleared the code, and like 2 days later..same P0175 code again. So I figured not the MAF.

Next I was thinking the same basic idea with the upstream o2 sensors. So I swapped those from one side to the other. Cleared the code and the next day the code is back..same side, bank 1 system rich.

My mechanic is saying injectors. I am just not convinced thats what it is. It drives 100%, no misfires, no smoke, no hesitations. And I don't want to go and throw $1000 worth of injectors at this and have it be something else.

Anyone have any ideas?

M6Roar · 10-01-2021, 05:20 AM

A smoke test will only reveal the obvious ones but not the one shows under pressure.

A vacuum leak can cause that too, a datalog if possible might help pinpoint the issue.
Also, you can check your injectors using ISTA.

e code · 10-01-2021, 08:09 AM

If I data log, what parameters should I be looking at? I dont have ISTA, is there anything I can look at while data logging that would give away the issue?

M6Roar · 10-01-2021, 08:43 AM

If your issue is more of a vacuum leak you will see a drop in the wgdc, if it more of boost leak you will find that the wdgc is too high. Look at your AFR, check you cylinder timings see if one is going crazy. Compare between DME 1 and DME 2.

You can download ISTA it will help you alot.

e code · 10-01-2021, 08:48 AM

Im on a Mac, I don't believe I can get it for Mac.

09-30-2021, 03:25 PM	#1
e code New Member 5 Rep 5 Posts Drives: 13 M5, 11 X5 Join Date: Aug 2019 Location: Albany, NY iTrader: (0)	P0175 Bank 2 System Rich Code Hey all, I have searched for info on my issue forwards backwards and sideways. I have been trying to diagnose this code for the better part of a year now. The code is intermittent but lately the CEL has stayed on. No real symptoms other than a slightly lower than usual idle, talking like maybe 50 rpms off. Gas mileage is fine currently averaging 22.5mpg. Still pulls like a freight train. It's on a mission tuning stage one tune FYI. Heres what I have tried: I put a smoker on it and no leaks from either bank. I cleaned the MAFs and cleared the code like 8 months ago. The code didnt come back for a couple months of daily driving. Figured it was a dirty MAF or it needed to be replaced. The code came back but its only bank 2 so I figured if its the MAF then if I swap one side for another then the code would switch to bank 1 giving me a P0172. So I swapped sides with the MAFs, cleared the code, and like 2 days later..same P0175 code again. So I figured not the MAF. Next I was thinking the same basic idea with the upstream o2 sensors. So I swapped those from one side to the other. Cleared the code and the next day the code is back..same side, bank 1 system rich. My mechanic is saying injectors. I am just not convinced thats what it is. It drives 100%, no misfires, no smoke, no hesitations. And I don't want to go and throw $1000 worth of injectors at this and have it be something else. Anyone have any ideas?
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10-01-2021, 05:20 AM	#2
M6Roar Second Lieutenant 86 Rep 242 Posts Drives: '14 M6GC Join Date: Apr 2018 Location: Bahrain iTrader: (0)	A smoke test will only reveal the obvious ones but not the one shows under pressure. A vacuum leak can cause that too, a datalog if possible might help pinpoint the issue. Also, you can check your injectors using ISTA.
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10-01-2021, 08:09 AM	#3
e code New Member 5 Rep 5 Posts Drives: 13 M5, 11 X5 Join Date: Aug 2019 Location: Albany, NY iTrader: (0)	If I data log, what parameters should I be looking at? I dont have ISTA, is there anything I can look at while data logging that would give away the issue?
	Appreciate 0 Quote

10-01-2021, 08:43 AM	#4
M6Roar Second Lieutenant 86 Rep 242 Posts Drives: '14 M6GC Join Date: Apr 2018 Location: Bahrain iTrader: (0)	If your issue is more of a vacuum leak you will see a drop in the wgdc, if it more of boost leak you will find that the wdgc is too high. Look at your AFR, check you cylinder timings see if one is going crazy. Compare between DME 1 and DME 2. You can download ISTA it will help you alot.
	Appreciate 0 Quote

10-01-2021, 08:48 AM	#5
e code New Member 5 Rep 5 Posts Drives: 13 M5, 11 X5 Join Date: Aug 2019 Location: Albany, NY iTrader: (0)	Im on a Mac, I don't believe I can get it for Mac.
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