Hey folks-
I have been chasing down a problem for weeks that I can't seem to figure out. Car is a 325is with S52, OBD2. I'm also running the Turner M50 manifold adapter kit for OBD2. My car is running the 2 preCat O2 sensors only. The postCat sensors have been flashed out. Car has run for several years w/o throwing codes but now I keep getting combinations of the following faults:
- preCat O2 sensor voltage, Cyl # 1-3
- O2 sensor control limit, Cyl # 1-3
- O2 sensor control limit, Cyl # 4-6
- O2 sensor adaptation limit, Cyl # 1-3
- O2 sensor adaptation limit, Cyl # 4-6
I felt like everything pointed to a vacuum leak, so I removed, checked, and reinstalled all of the lines. I smoke-tested and discovered that I had a blown dipstick tube o-ring and a very slight leak at the seal between the CCV and the intake. I replaced both of those seals expecting the problem to go away, but the same codes persisted. Just to be even more thorough, I replaced the CCV and all related lines and seals, as well as the O2 sensors. None of that made a difference. The car idles and runs perfectly, not exhibiting any misses and the power delivery is smooth and 'normal' feeling. The codes I listed are taken from my Peake reader but I've also connected to the ECU via my Torque app on my phone to compare the readings. The codes have slightly different descriptions but seem to be consistent with what the Peake is reporting. There is one very strange thing, though. Torque is showing a consistent 0% reading for the short term fuel trims on both banks. However, to be fair I'm not 100% sure that the converter cable that connects my engine compartment round connector to my bluetooth OBD reader can be trusted. All other realtime data is showing properly in Torque, but the fuel trims are not changing. Could this be a clue? If so, is it possible I have an issue with my ECU maybe or even the wiring? I have confirmed I'm getting voltage to both of the O2 sensors. At this point I'm totally stumped and would appreciate any insight y'all can share!
I have been chasing down a problem for weeks that I can't seem to figure out. Car is a 325is with S52, OBD2. I'm also running the Turner M50 manifold adapter kit for OBD2. My car is running the 2 preCat O2 sensors only. The postCat sensors have been flashed out. Car has run for several years w/o throwing codes but now I keep getting combinations of the following faults:
- preCat O2 sensor voltage, Cyl # 1-3
- O2 sensor control limit, Cyl # 1-3
- O2 sensor control limit, Cyl # 4-6
- O2 sensor adaptation limit, Cyl # 1-3
- O2 sensor adaptation limit, Cyl # 4-6
I felt like everything pointed to a vacuum leak, so I removed, checked, and reinstalled all of the lines. I smoke-tested and discovered that I had a blown dipstick tube o-ring and a very slight leak at the seal between the CCV and the intake. I replaced both of those seals expecting the problem to go away, but the same codes persisted. Just to be even more thorough, I replaced the CCV and all related lines and seals, as well as the O2 sensors. None of that made a difference. The car idles and runs perfectly, not exhibiting any misses and the power delivery is smooth and 'normal' feeling. The codes I listed are taken from my Peake reader but I've also connected to the ECU via my Torque app on my phone to compare the readings. The codes have slightly different descriptions but seem to be consistent with what the Peake is reporting. There is one very strange thing, though. Torque is showing a consistent 0% reading for the short term fuel trims on both banks. However, to be fair I'm not 100% sure that the converter cable that connects my engine compartment round connector to my bluetooth OBD reader can be trusted. All other realtime data is showing properly in Torque, but the fuel trims are not changing. Could this be a clue? If so, is it possible I have an issue with my ECU maybe or even the wiring? I have confirmed I'm getting voltage to both of the O2 sensors. At this point I'm totally stumped and would appreciate any insight y'all can share!
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