O2 Sensor replacement '88 300E
 

Is this a DIY kinda job? It looks straight forward enough... is there a trick to guiding the floorboard type bushing into it's hole?

thanks

Ken

Just did that job the other day.
Un plug the sensor wire under passenger carpet, attach a string to the lead so you have something to pull the new lead through with, then push it thru. the floor so it is outside the car. The wire needs to rotate with the 02 sensor as you unscrew it or it keeps winding itself back into its threads as the wire trys to uncoil itself. I found it easier to thread the wire connector through the ring end of the wrench (22mm) and loosening from the passenger side of the exhaust. My wrench has a slight angle to it and I was able to get a good purchase on the 02 sensor. Once its out replace with new 02 sensor after attaching the pull string to the leads. Once the cable enters the car the rubber grommet can be fed into the hole.
This explanaition was too long but I hope you gat the idea.

Michael

jackstands will be enough to get to the O2 sufficiently and working the grommet into its hole... with a screwdriver or what?

thanks

i didn't even you jackstands.....

sort of fiddled with a screwdriver..... i used a generic three wire sensor...so it was more of a pain splicing the wires together.... but the sensor was less thand 30 dollars... and now i get 3 more miles to the gallon...

carnac, automotive stores sell an offset wrench (basically an open end wrench with a slot) for installation/removal of Oxygen sensors. The wrench costs around $10 and fits over the electrical lead. Remove the passenger side carpet insert and unplug the electrical lead. From below the car push the grommet into the passenger compartment so the electrical lead is free and clear. Then unscrew the Oxygen sensor and remove. Installation of new Oxygen sensor is reverse order. Make sure there is a coating of Never-Seeze on the Oxygen sensor threads ... makes removal the next time much easier.

I found access much easier from the passenger side after I removed the brackets and supports around the exhaust pipes. Autozone has the socket under its free loaner program.

I just did it 2 weeks ago on my 300TE.

It was pretty straight forward.

I posted this a few weeks ago. I think you have an M103 as well so should be the same. Even if you have a different engine the basics should apply.

http://www.peachparts.com/shopforum/tech-help/211060-w126-02-sensor-replacement-intallation.html?highlight=w126+oxygen

Great info - thanks very much, I need to do this too.
Does the new sensor need to be installed with a torque wrench, or how tight should it be?