Premium Member 2013 SLK250
A year ago on my 2001 230 replaced O2 sensor as CEL came on the the code was O2 sensor bank 1 was bad. Replaced it and today a year later and 10,000 miles the CEL came on again. Code is O2 senor bank 1 is bad, reset it and with end 5 miles CEL came back as O2 sensor is bad. Before I replace it does anyone have a suggestion why it would go bad in a years time. Gas milage is good and runs good and no oil or coolant lost. Senor is clean and dry, no oil on it. It is costly to replace, around 400 US (parts and labor). Just a few weeks over a year therefore not covered by a warrenty replacement.