2013 CLS 550 o2 Sensor Replacement
Thread Starter
Newbie
Joined: Sep 2017
Posts: 8
Likes: 3
From: SF Bay Area
2012 CLS 550
2013 CLS 550 o2 Sensor Replacement
Hello,
Anyone replaced their bank 1, upstream o2 sensor? Any insight as to accessing it? Is it accessible from underneath the hood or under body?
Or does anyone have a schematic or link to such info?
Thank you!
Anyone replaced their bank 1, upstream o2 sensor? Any insight as to accessing it? Is it accessible from underneath the hood or under body?
Or does anyone have a schematic or link to such info?
Thank you!
Super Member
Joined: Jan 2017
Posts: 744
Likes: 144
From: Bay Area
W218 Stage 2, E85
yes, it will be from underneath. You're going to have to wiggle yourself and get in there. It would be essential to lift the car up. If the bolt is pretty tight, def need a lift. If it's not too tight or not "jammed," then you can put it up on ramps and access it from down below. I had a hard time removing it and used various O2 sensor removal wrenches/sockets. Please let me know which did you end up using or how easy/hard was it to remove it for future purposes.
Thread Starter
Newbie
Joined: Sep 2017
Posts: 8
Likes: 3
From: SF Bay Area
2012 CLS 550
I just took a look at it. I had to jack the car up just to get underneath. I see the upstream sensor and the connection point. I think your're right about leverage issues with the limited access. I may spray it with something and let it sit before trying to break it. Will keep you posted, thanks
Thread Starter
Newbie
Joined: Sep 2017
Posts: 8
Likes: 3
From: SF Bay Area
2012 CLS 550
Just completed the install. You will need to jack the car up pretty high. Remove the middle under body plastic shroud, I think there are eight 8mm screws holding it in. I sprayed some liquid wrench on the sensor then removed the shroud to let it penetrate. I had to go under the front of the car, going from the side doesn't work
Aligning the socket wrench to the o2 socket was a little tricky but it broke loose pretty easily once I got it on. It was a $6 socket head from Rock Auto that was one of many suggested for this. It's pretty flush which I believe makes the job easier. The plug was about $50, which was the cheapest I could find even amongst mbpartsdirect etc.
The plug is affixed to the housing of the transmission. Remove the coupled plug out of the metal clips. Once out I had to lay flat on my back and reach up with both hands to release the plastic clip, there's very little slack. After that it was pretty straight forward for reinstall. Make sure to clean threads on exhaust, then finger tighten the sensor (do not plug in until it is completely tightened). Per Bosch do not over tighten as the heat will expand the metal/threads. No additional anti seize is required. Plug in new sensor. There are little grooves that the coupled connection slips onto on the metal bracket. Reinstall shroud.
Last edited by DanielW415; May 17, 2020 at 03:59 PM. Reason: spelling correction
Super Member
Joined: Jan 2017
Posts: 744
Likes: 144
From: Bay Area
W218 Stage 2, E85
Ahhh, so you used the flex head with that one. Ok. I was using the flex head wrench.
Did you have any clearance/space issue with the flex head? My O2 sensor was heavily tightened, so it took a lot more force to remove it. The lift was necessary in my case even after spraying WD40.
Removing the clips off the sensor deep in there was very uncomfortable for me as well haha. It started to frustrate me.
I'm glad you got it done quickly. I struggled for 2 days before I took it to my friend's shop haha. Thanks for the info tho!
Did you have any clearance/space issue with the flex head? My O2 sensor was heavily tightened, so it took a lot more force to remove it. The lift was necessary in my case even after spraying WD40.
Removing the clips off the sensor deep in there was very uncomfortable for me as well haha. It started to frustrate me.
I'm glad you got it done quickly. I struggled for 2 days before I took it to my friend's shop haha. Thanks for the info tho!
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Thread Starter
Newbie
Joined: Sep 2017
Posts: 8
Likes: 3
From: SF Bay Area
2012 CLS 550
Ahhh, so you used the flex head with that one. Ok. I was using the flex head wrench.
Did you have any clearance/space issue with the flex head? My O2 sensor was heavily tightened, so it took a lot more force to remove it. The lift was necessary in my case even after spraying WD40.
Removing the clips off the sensor deep in there was very uncomfortable for me as well haha. It started to frustrate me.
I'm glad you got it done quickly. I struggled for 2 days before I took it to my friend's shop haha. Thanks for the info tho!
Did you have any clearance/space issue with the flex head? My O2 sensor was heavily tightened, so it took a lot more force to remove it. The lift was necessary in my case even after spraying WD40.
Removing the clips off the sensor deep in there was very uncomfortable for me as well haha. It started to frustrate me.
I'm glad you got it done quickly. I struggled for 2 days before I took it to my friend's shop haha. Thanks for the info tho!
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Thread Starter
Newbie
Joined: Sep 2017
Posts: 8
Likes: 3
From: SF Bay Area
2012 CLS 550
I feel that this flush fit socket probably was key for removing the upstream sensor. Some of these sockets are deep and I can't imagine getting one on the sensor in this location.
Super Member
Joined: Jan 2017
Posts: 744
Likes: 144
From: Bay Area
W218 Stage 2, E85
If the O2 sensor is really dead, you'll get the code back almost instantaneously or within a few days of clearing the code.
Senior Member
Joined: May 2019
Posts: 353
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2014 CLS 550
Did it go away by itself or you had it cleared? What I usually do if there is a CEL, I usually check it and clear it and observe how the car behaves from that point and see if it comes back and in the meantime, try to find if what could've been the reason before going to replace it. Me personally, I'd wait till it comes back again. If the sensor literally dies out, 0% functionality, it'll throw misfire codes as well. But that takes a while. At the beginning of the O2 sensor failing times, you'll feel the loss of power sometimes before you actually get a code. That may not be true in your case, but it happened to me with this car last year. So keep an open mind and observe the acceleration of the car.
If the O2 sensor is really dead, you'll get the code back almost instantaneously or within a few days of clearing the code.
If the O2 sensor is really dead, you'll get the code back almost instantaneously or within a few days of clearing the code.
i actually noticed something that never happened before I was accelerating and it jumped really bad from 3 to 4th like I thought something was wrong with the car and it’s never happened before and it hasn’t happened again. I thought it was weird but The light went off by itself never had it cleared
Super Member
Joined: Jan 2017
Posts: 744
Likes: 144
From: Bay Area
W218 Stage 2, E85
i actually noticed something that never happened before I was accelerating and it jumped really bad from 3 to 4th like I thought something was wrong with the car and it’s never happened before and it hasn’t happened again. I thought it was weird but The light went off by itself never had it cleared
Honestly, I don't have any knowledge or a clue why that jerk might've happened. I haven't experienced that.
Senior Member
Joined: May 2019
Posts: 353
Likes: 56
2014 CLS 550
Super Member
Joined: Jan 2017
Posts: 744
Likes: 144
From: Bay Area
W218 Stage 2, E85
yeah not sure if the engine was cold now that I think about it and it’s not tuned, yet. Yeah I was pissed when it happened and so far hasn’t happened. I’m getting battery replaced tomorrow. My parking sensors haven’t been working about half the time and it’s getting annoying. Weird the check engine light hasn’t came back on for the o2 sensor.
My sister's C250 had a transmission sensor CEL come up...we cleared it, it took a month for it come back, again. We cleared it again, it hasn't come back since lol. Though it gave another CEL for a bad thermostat, which we replaced. But now...it has a CEL, but no code. Took it to a shop...no code. Light is still on lol. Took the battery cables off/on, still there. So I'm going to take it to a diff shop soon and see if they can figure something out.
