On your dash, use a flashlight (or not if the symbols are clearly legible) to light up the warning lights. On some cars, particulary earlier ones, I believe that there might have been a "Lambda Sensor" warning light. As to the reliability of these, I don't know. There shouldn't be anything to reset-just plug in (or rewire) the new sensor. The engine reads the correct inputs and adjusts the fueling system accordingly.

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2002 Mercedes-Benz E320 4Matic
1995 Mercedes-Benz E320 Wagon
2005 Land Rover LR3 V8 SE
1999 Audi A8 4.2L quattro