BOARD OF SENSORS

Gareth Owen

Your correspondent Stephen Ward says that Lambda sensors only have a working life of about 60,000 miles or six years (Dealer’s Diary, January 2017). My 2007 Mercedes-benz E320 CDI is nearly 10 years old and has 95,000 miles on the clock. I have always been keen on preventive maintenance and replacing things before they let me down miles from home. I believe the E320 CDI has four Lambda sensors and would therefore set me back more than £500 to replace them, even fitting them myself. Do you recommend I go ahead and replace them?