Are my O2 sensors leaving the chat?

BMWdmk · 08-17-2023, 11:01 AM

Chasing down this pesky issue with fuel trims and I think I'm narrowing it down to my pre cat sensors before getting on boost. Anyone have any experience with lazy o2 sensors or funky high readings off gas?

N54 MT MHD ST2+

https://datazap.me/u/dkal88/log-1692...&data=14-15-22

UPDATE 8/20

Replaced intake manifold gaskets and throttle body gasket also had an extra mann oil filter O ring that I threw in the chargepipe. Gave everything proper torque spec and the weird afr jump is gone (log below).

The original gaskets looked pretty worn and smaller than new.

https://datazap.me/u/dkal88/log-1692...&data=15-16-23

Don't change your o2 sensors if this is what you have going on with your afrs

BMWdmk · 08-20-2023, 12:30 PM

Solved. Info attached

08-17-2023, 11:01 AM	#1
BMWdmk Rollin 3rd 106 Rep 1,232 Posts Drives: Something fast Join Date: Sep 2007 Location: Chino Hills iTrader: (15)	Are my O2 sensors leaving the chat? - SOLVED Chasing down this pesky issue with fuel trims and I think I'm narrowing it down to my pre cat sensors before getting on boost. Anyone have any experience with lazy o2 sensors or funky high readings off gas? N54 MT MHD ST2+ https://datazap.me/u/dkal88/log-1692...&data=14-15-22 UPDATE 8/20 Replaced intake manifold gaskets and throttle body gasket also had an extra mann oil filter O ring that I threw in the chargepipe. Gave everything proper torque spec and the weird afr jump is gone (log below). The original gaskets looked pretty worn and smaller than new. https://datazap.me/u/dkal88/log-1692...&data=15-16-23 Don't change your o2 sensors if this is what you have going on with your afrs Last edited by BMWdmk; 08-20-2023 at 12:29 PM.. Reason: Solved issue
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08-20-2023, 12:30 PM	#2
BMWdmk Rollin 3rd 106 Rep 1,232 Posts Drives: Something fast Join Date: Sep 2007 Location: Chino Hills iTrader: (15)	Solved. Info attached
	Appreciate 0 Quote