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Lambda/AFR problems

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I noticed a couple of weeks ago that my Lambda #1 was not giving any sensor information and the temperature is indicating a constant 32 degrees. Now the #2 Lambda is indicating an AFR around 45-50 at idle. Nothing has been changed in the last couple weeks except for an ECU update. Even then the lambda #2 worked fine. It wasn't until today the it started acting up. Any ideas?


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Everything is current and up to date. From looking at the logs the problem started yesterday morning in the middle of an idle run. The only thing I can think of is something with the internal lambda controller was changed when I was configuring the CAN settings for the AIM MXS Strada I purchased.

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Didnt you have a log attached earlier?  There is no way firmware or PC link could cause what you are seeing.  It looks like sensor 1 has failed.  Sensor 2 is giving funny results but all the dianostics look ok and it seems to be showing some response to AFR.  So on bank two I would be leaning more towards an air leak or a cylinder misfiring on bank 2?

A quick test will be to swap sensors side to side and see what clues that gives.  

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Thanks, I have a replacement O2 sensor for bank #1 arriving today. I'll see what I get with that and will check for an air leak while its up. Everything appears to be running fine though.


https://www.dropbox.com/s/o12jrkwzkio9o99/AFR gone wild.llg?dl=0

https://www.dropbox.com/s/5g18oguau7ov7dt/AFR gone wild.csv?dl=0

So, I've swapped the 2 sensors and the problems follow. #2 goes dead and #1 now indicates an AFR ranging between 45-120. I'm not finding any air leaks either.


The new O2 sensor on bank 1 seems to have fixed that problem. Now the one on bank 2 has completely failed and is only heating to 65 degrees. I have 2 more sensors on the way so I'll have a spare.


Thanks for the help

Edited by Usav8or
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