2018 Mercedes-Benz P0133: What It Means & Is It Safe to Drive?

P0133 on the 2018 Mercedes-Benz: O2 Sensor Slow Response (Bank 1, Sensor 1). Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.

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What this code means

The upstream oxygen sensor on Bank 1 is responding too slowly to changes in exhaust composition. A healthy O2 sensor switches between rich and lean several times per second; a sluggish sensor causes poor fuel control.

Common causes on the 2018 Mercedes-Benz

  • Aging or contaminated upstream oxygen sensor
  • Oil or coolant contamination fouling the sensor
  • Carbon buildup on the sensor tip
  • Weak heater circuit in the sensor

Symptoms

  • Check Engine Light
  • Slightly decreased fuel economy
  • Possible rough idle
  • Failed emissions test

Typical fixes

  • Replace upstream oxygen sensor
  • Check for oil/coolant burning that could foul new sensor

Repair cost range

For a 2018 Mercedes-Benz, repairs for P0133 typically fall between $100 and $300, depending on the root cause and labor rates in your area.

Is it safe to keep driving your 2018 Mercedes-Benz with this code?

For driving-safety guidance—how far you can go, when to tow, and what's urgent—see these checklists:

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