Hey guys, recently ran into a issue with my C55 AMG with 209,000 miles showing the check engine light. code was P2097. BANK 1 POST CAT TOO LEAN. i just replaced the downsteam O2 sensor on the passenger side(US) with a used bosch original C55 o2 sensor and the check engine light resolved itself after a few days after installation. pretty weird it went away after a couple days after i changed it but i am not complaining. i am glad because i was erasing the code and it was still coming back. im sure you have to reset the adaptions, but on the AUTEL device i was using i couldnt seem to find the menu to do so. i was worried my catalytic converter was bad or even worse but no it was just a sensor luckily. figured it would be useful to someone else. this information could be used for other Mercedes as well. after replacement the idle