Oxygen Sensor Replacement Estimate for Mercedes-Benz 420SEL

Mercedes-Benz 420SEL Oxygen Sensor Replacement costs $211 on average. Following is a breakdown of the labor and parts estimates.

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YourMechanic Price
$211 to $221
Labor: $70 -$80
Parts: $141
Average Dealer price
$374
Average Shop price
$259
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CarServiceYourMechanic PriceShop/Dealer Price
1989 Mercedes-Benz 420SELV8-4.2LService typeOxygen Sensor - Rear/Lower/Downstream ReplacementYourMechanic Price$221.95Shop/Dealer Price$285.34 - $418.36
1990 Mercedes-Benz 420SELV8-4.2LService typeOxygen Sensor - Rear/Lower/Downstream ReplacementYourMechanic Price$219.13Shop/Dealer Price$281.95 - $412.95
1991 Mercedes-Benz 420SELV8-4.2LService typeOxygen Sensor - Front/Upper/Upstream ReplacementYourMechanic Price$219.13Shop/Dealer Price$281.87 - $412.81
1989 Mercedes-Benz 420SELV8-4.2LService typeOxygen Sensor - Front/Upper/Upstream ReplacementYourMechanic Price$219.13Shop/Dealer Price$281.91 - $412.87
1990 Mercedes-Benz 420SELV8-4.2LService typeOxygen Sensor - Front/Upper/Upstream ReplacementYourMechanic Price$221.95Shop/Dealer Price$285.36 - $418.39
1991 Mercedes-Benz 420SELV8-4.2LService typeOxygen Sensor - Rear/Lower/Downstream ReplacementYourMechanic Price$221.95Shop/Dealer Price$285.33 - $418.34
1988 Mercedes-Benz 420SELV8-4.2LService typeOxygen Sensor - Front/Upper/Upstream ReplacementYourMechanic Price$222.65Shop/Dealer Price$286.37 - $420.03
1988 Mercedes-Benz 420SELV8-4.2LService typeOxygen Sensor - Rear/Lower/Downstream ReplacementYourMechanic Price$219.13Shop/Dealer Price$281.94 - $412.94
Show example Mercedes-Benz 420SEL Oxygen Sensor Replacement prices

Parts required for a Mercedes-Benz 420SEL Oxygen Sensor Replacement

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All about Oxygen Sensor Replacement

With each new model year, manufacturers are adding more oxygen sensors to better manage engine operation. Some high performance engines have an oxygen sensor for each cylinder as well as one for the rear of each catalytic convertor. The sensors are located either underneath the hood or underneath the car. The oxygen sensors are connected (screwed) to the exhaust pipe, either in front or back of the catalytic converter. The front (upstream) sensors measure the amount of oxygen in the exhaust system. The purpose of the front oxygen sensor(s) is to measure how rich or lean the gases are as the gases exit the combustion chamber. Depending upon whether the exhaust gas is lean (high in oxygen content) or rich (low in oxygen content), the amount of fuel entering the engine is adjusted by the engine management computer to try and maintain an ideal mixture that produces the lowest emissions output from the catalytic convertor. Rear (downstream) sensors are located behind the catalytic converter. The purpose of the rear oxygen sensor(s) is to monitor the oxygen content of the exhaust gases leaving the catalytic convertor. If one or more of the oxygen sensors are faulty, your car may not pass the emissions test. If you drive your car with a faulty oxygen sensor, you may get poor gas mileage and it can damage the catalytic converter.

Oxygen Sensor Replacement Estimates for Popular Mercedes-Benz Models