Columbus430

Had a code for an O2 sensor, O2 sensor delayed response. It only happened once and after I cleared it it never happened again.
I have 150,000 miles, should I replace it anyways? If I replace one should I replace all 4? Is there a recommended set of aftermarket O2 sensors?

I also had a code for "Humidity/Temperature sensor has a malfunction. Internal electrical fault". Is this a sensor I can get to and replace? Where is it and what is the part number?

Thanks for the input.

oldmangrimes

If it's temp/humidity then I think it's the internal sensor, the part number I found was A1729058200 (it common with other Mercedes models). If it is, here's a diagram: https://www.mbpartscenter.com/oem-pa...sor-1729058200
But I don't know for sure if it's that sensor.

chassis

150k miles is not unheard of for O2 sensor replacement.

Pull the connector apart and check for signs of oil.

Also pull the cam sensors and cam magnet connectors apart and check for oil.

reg8667

i bought the two rear O2 sensors on fcp and was going to install them myself, but I had the car in for tire rotate and balance so I asked them replace then for me while they had the car up. Easy Peasy. 115k miles on the clock. Cleared cel twice and it kept coming back so went ahead and replaced both rears even though only the left bank was coding. I wish I would have gotten the promised bump in gas mileage, but that never happened.

Columbus430

I found this O2 sensor at FCP, but it says it's for the rear position.

Bosch 0085423918

I can't find one that states it's for the front position. Does someone have that PN?

mcoady1

My '13 @ 128k has been having that code on and off for years, typically once every 3 months. I'm ignoring for now, but let us know what you find on yours.

mcoady1

Did you end up replacing O2 sensor?

Just discovered oil in my cam sensors - magnets are dry. Had this same code and was wondering if you replaced O2 sensors and/or found oil in the connectors? If so, any performance change?