has anybody followed up on changing their o2 sensor? i am in dire need of changing it, and if easy enough make it a DIY.

 

Read this thread completely and you'll have your answers.

https://mbworld.org/forums/e-class-w124/113368-good-bad-gas-mileage.html

 

I changed my O2 sensor last week. Easy job, can be done by novice D.I.Y. I ordered the M.B. sensor from the BenzBin.com I think it was about $110 or so. I decided to go with that rather than try and buy the cheaper sensor and splice it into the wiring harness. Jack the front end up, make sure you have safety jack stands and emergency brake on. Get a pair of channel lock grips or some type of large adjustable wrench. I forget what size the nut is on top of the sensor, but just use the new one to size it up. Sensor is located on top of the exhaust manifold right before the cat. converter. It will probably be rusted on to the manifold, (Try and change it with the car engine totally cold) you might be able to put the wrench onto the old sensor and then use a piece of pipe as a breaker bar on the wrench to get enough torque to break it loose. Unscrew the old one, then pull up the carpeting and foam on the front passenger side floorpan. You will see where the O2 sensor wires come in and plug into. Unlpug the old and feed the old wires through the hole in the frame. Screw in the new sensor underneath and then feed the new wires through the hole into the floor pan (helps if you have somebody inside the car to grab the new wires and pull them through. Plug in the new wires and you're good to go. Shouldn't take more than an hour. I was really pleased with myself when I found out my Dr. brother-in-law paid $500 to have his O2 sensor changed on his C280.

 

How many does your car have ? Why didn't you do them all ?

 

Nice DIY. thanks! I'll check it out for myself and possibly change that soon along with a new air filter an do a Tune up later sometime next month.

I might make a W124 DIY Topic later, anyone think thats a good idea? It would be better so we dont have to search throughout the whole W124 section for DIY stuff we saw in the past.

 

There's only one on the W124.

 

Lucky you , I've got 4 of them that I gotta change - not looking forward to this project.

 

How do you find out that the CO2 sensor needs to be changed? What does the car do when its bad? Or is it just a maintenace item, like spark plugs or something like that?

 

thanks for the diy writeup, im going to need to look at it when i get some time soon. i think it just destroyed my cat because its running too rich.

 

when you mpg is low and you haven't replaced it for about 50k miles... i think

 

Seriously look into the Bosch O2 sensor for a 1990 Mustang 302 (I think). It is MUCH cheaper than the Bosch version for MB. You need a watertight plug connection from the Ford dealer. There was a site with detailed info on this job, but it is no longer around.