What does code P0133 mean on a Mercedes-Benz and is it safe to drive?
P0133: O2 Sensor Slow Response (Bank 1, Sensor 1). Here's what it means on your Mercedes-Benz, what usually causes it, what repairs typically cost, and how safe it is 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 for your 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 Mercedes-Benz, repairs for P0133 often fall between $100 and $300, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.