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09-25-2023LAST POST
Been having these codes pop up now for awhile and have been just clearing them and but eventually they come back after days/weeks. Any ideas? I am thinking it's o2's or some sensor. At first it was just 27BB then the other two started popping up as well.

// 2) 27BB Fuel system diagnostic bank 2
// 3) 27C7 Lambda sensor trim control AD diagnostic bank 2
// 4) 2727 Lambda sensor plausibility VKAT bank 2
I'm sure there's been discussions about this topic but not sure any resolutions identified.

From my personal experience having dealt with the same error code, I ended up replacing the pre-CAT O2 sensor, but the code came back. Eventually, the car went into limp mode and a bunch of other codes appeared.

In short, it turned out the spark plugs were causing this and all codes disappeared and have not come back after replacing them. This was done about three months ago. BTW, the car runs much better with a bit more responsiveness throughout lower end of the rmps in all gears.

Hope this helps.
cloumeM wrote
I'm sure there's been discussions about this topic but not sure any resolutions identified.

From my personal experience having dealt with the same error code, I ended up replacing the pre-CAT O2 sensor, but the code came back. Eventually, the car went into limp mode and a bunch of other codes appeared.

In short, it turned out the spark plugs were causing this and all codes disappeared and have not come back after replacing them. This was done about three months ago. BTW, the car runs much better with a bit more responsiveness throughout lower end of the rmps in all gears.

Hope this helps.
Damn the spark plugs were replaced just 7k miles ago. You think it’s worth trying to replace the sensors first? Or just do both?
Check out this thread here for discussion about the low pressure fuel sensor and code 27BB.
And this thread for a DIY for the low pressure fuel sensor.
rjsiciliano wrote
Damn the spark plugs were replaced just 7k miles ago. You think it’s worth trying to replace the sensors first? Or just do both?
Oh, that's too recent to cause any issues I think... Maybe O2 sensor? Worth checking the link to discussion provided by the post above.