M54B30 lambda/O2 sensor malfunction

[imbiling]

Hello,


Please take a look at the following video. The car was driven at a steady 50KPH most of the time. Both Bank 2 sensors are showing lean measurement.


1. Are Bank 1 sensors cycling interval fast enough? Is the O2 sensor becoming lazy?
2. What's your opinion on the lean mixture reported most of the time by bank 2 sensors?


I know that only pre-cat sensors are used by the ECU for mixture information. I'm planning to replace them both. Any opinion/advice will be welcome.

[328 Power 04]

You can't go by that data because the refresh rate is too slow. Any error codes?
Replace both sensors with new, and have a good car.

[jakermac]

And make sure that the front bank sensor is wired to the front bank of cylinders and vice versa. Imagine what happens if the front sensor is reporting back to the DME the conditions of the rear bank (and vice-versa), but the DME is making corrections to the front bank because the signal is being fed into the DME as "front bank". My buddy scratched his head for a very long time until we talked things through for a while and discovered that he'd mixed up the wiring because he bought generic sensors that needed wired in.

[imbiling]

I also thought that the refresh rate might be very low. Occasionally an error is thrown that the heater of bank 2 sensor 1's heating is not working. This is the same sensor which rarely changes its value in the video. I will buy two Bosh pre-cat lambda sensors with part numbers 11781742050 in a couple of weeks and I will report back the difference. jakermac, I will take what you said into account.

The fuel consumption seems high although I don't have a reference for comparison.