When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi all,
So I got P013E00 (Oxygen Sensor 2 - cylinder bank1) and P014a00 (Oxygen Sensor 2 - cylinder bank2) delayed. When trying to find the parts at FCP, there are 2 sensor in the front and 2 in the rear and they all fit my car. I am confused. I thought my car (13 cls63 M157) has only 2 Oxygen sensors. Does anyone knows anything about this?
How difficult to replace those bad sensors? Where are they located?
Thanks.
Hi all,
So I got P013E00 (Oxygen Sensor 2 - cylinder bank1) and P014a00 (Oxygen Sensor 2 - cylinder bank2) delayed. When trying to find the parts at FCP, there are 2 sensor in the front and 2 in the rear and they all fit my car.
I am confused. I thought my car (13 cls63 M157) has only 2 Oxygen sensors. Does anyone knows anything about this?
How difficult to replace those bad sensors? Where are they located?
Thanks.
Just about every modern gasoline engine uses a combination of Lambda sensor plus Oxygen sensor.
The primary upstream sensor after exhaust valves is a Lambda (wide-band) sensor then comes a catalytic converter followed by the O2 (narrow band) that is of concern here.
> THINK TWICE:
It's odd that secondary O2 be bad together at once and primary Lambda be ok.
Right your O2 codes flag poor scrubbing by the dirty old or melted cats.
Both cats, both sensors at once!!
> In your case both sensors popped a fault jointly. What does that tell you?
... it's the engine or the cats, not the sensors.
Do you have non-stock mods to tweak engine mixture ?
> Can you read the ECU Fuel Trims for both engine banks? This will help you address the root cause of present "O2 faults".
If you're in the mood for tune-up parts: replace the upstream Lambda now! They are a key input that drives the ECU fuel map.
Put it this way: if your Lambda were good, the cats would have an easy task scrubbing and the O2 would have no issue.
> REGARDLESS:
You may replace secondary O2 now... but don't expect those sensors to help the current set of faults.
Buy the special O2 socket to muscle these hot rusted parts. Spray "PB Blaster" to help loosen threads.
Last edited by CaliBenzDriver; 02-16-2024 at 04:57 PM.
My car is stock. All I have is resonator deleted. I try to replace both O2 sensors for now. I have not found any video to replace the O2 sensor for this car. Other cars/models have upstream & downstream 02 sensors. I assume mine have those as well. Do I need to replace all 4 sensors? Thank you.
My car is stock. All I have is resonator deleted. I try to replace both O2 sensors for now. I have not found any video to replace the O2 sensor for this car. Other cars/models have upstream & downstream 02 sensors. I assume mine have those as well. Do I need to replace all 4 sensors?
Thank you.
Yes, that will be very beneficial.
90% chances the new upstreams will restore engine youth plus much improved throttle response.
These sensors are the personal advisors to her majesty the ECU. Lambdas measure how well the combustions are executed.
Obviously plugs and injectors are common maintenance along with limp chain tensioners that screw up exact timings.
Last edited by CaliBenzDriver; 02-16-2024 at 04:58 PM.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Correct. Sensor 2 is after the cat. What happens when you erase the codes? They show STORED and not CURRENT.
40k miles is not a lot for the sensors to both go bad simultaneously. But your car is 11 years old. You could try replacing the O2 rear sensors--the only harm will be to your wallet. If you still have the problem, a test you could try is an old trick we used to use when a tuned car would throw a DTC. Get a spark plug non-fouler, which offsets the O2 sensor from the exhaust stream. If the problem went away, then the cat was probably bad. Of course, this may be considered illegal to drive the car on public roads where you live, so use at your own risk.
I use the L shaped one for my 24 year old truck, which no longer requires emissions testing, to eliminate the annoying CEL. Now, if I get a CEL in the truck, I know I have to look for another cause.
So, the sensor 2 is also name down stream or rear sensor and located after the catalytic converer. Am I correct?
Now you see that this is not a current fault... no parts necessary
At 40kMi the downstream sensors can only be clean so when the ECU flag both cats as bad at the same time... you got a transient condition.
Even with an engine drinking its oil can not mess up secondary sensors that fast, at least not before upstream!
Have a look at how your FUEL TRIMS are working :
High or right or low.
Last edited by CaliBenzDriver; 02-17-2024 at 12:31 PM.
The error came on and off a few times in a long preiod of time, around 6 months. I did get the "accelerator pedal sensor" and had it replaced already. I dont know if this code has anything to do with the pedal sensor I have replaced.
The error came on and off a few times in a long preiod of time, around 6 months.
I did get the "accelerator pedal sensor" and had it replaced already.
I dont know if this code has anything to do with the pedal sensor I have replaced.
The accelerator pedal is a classic standard fault linked to poor internal connection. There's no evidence to link it with the O2 sensors disfunctioning.
However it's interesting this fault repeats over a period of time. That definitely means something marginal is happening there.
Your engine being such low mileage with this type of code says nothing about your O2 being bad.
> FUEL ....
Go ahead and read live datastream under the ECU Module to find out what your long-term fuel trims are doing.
Marginal trims can clearly cause the "delayed cat response" type code.
These cars use a complex fuel delivery system with plenty of opportunities to be too lean. The LTFT will give you evidence of your engine abilities to regulate fuel delivery... Rich vs. Lean ??
Also scrutinize the rail fuel pressure particularly under acceleration conditions
> Driver Habits:
Do you warm up your engine before driving it ?? Your code flags cats not being hot enough to glow.
Last edited by CaliBenzDriver; 02-17-2024 at 01:55 PM.
I am only at 38,000KM or 23,600 miles but a10 years old M276 3.0 Turbo.
So I replaced all 4 sensors. 2 + 2 Front-s and Rear-s
The rear or narrow band oxygen sensors already a bit lazy. No DTC . I do not wait for DTC, as we can log rear oxygen sensors performance and
see if it is slow enough to be replaced, before DTC can happen.
Waiting for DTC for oxygen sensors or Lambda sensors is a bad practice, that means we wait for BAD performing components, which can damage your expensive CATs and poor performance of the engine.
The accelerator pedal is a classic standard fault linked to poor internal connection. There's no evidence to link it with the O2 sensors disfunctioning.
However it's interesting this fault repeats over a period of time. That definitely means something marginal is happening there.
Your engine being such low mileage with this type of code says nothing about your O2 being bad.
> FUEL ....
Go ahead and read live datastream under the ECU Module to find out what your long-term fuel trims are doing.
Marginal trims can clearly cause the "delayed cat response" type code.
These cars use a complex fuel delivery system with plenty of opportunities to be too lean. The LTFT will give you evidence of your engine abilities to regulate fuel delivery... Rich vs. Lean ??
Also scrutinize the rail fuel pressure particularly under acceleration conditions
> Driver Habits:
Do you warm up your engine before driving it ?? Your code flags cats not being hot enough to glow.
CEL has gone. It stayed for a couple days. The code came on and off, I admit that I did not read the code the last couple times it came up. Even the last time, I scan it after it's gone.
==> Your "Driver Habits" section got my attention. Thank you so much for this. I usually warm up the engine the first thing in the morning for 2 minutes but after the first drive, I just get in and drive, I don't want to make others wait for the parking spot.
Will try to read live data stream for long term fuel. I'm not familiar with this.
CEL has gone. It stayed for a couple days. The code came on and off, I admit that I did not read the code the last couple times it came up. Even the last time, I scan it after it's gone.
==> Your "Driver Habits" section got my attention. Thank you so much for this. I usually warm up the engine the first thing in the morning for 2 minutes but after the first drive, I just get in and drive, I don't want to make others wait for the parking spot.
Will try to read live data stream for long term fuel. I'm not familiar with this.
Thank you for sharing your expertise!!!
CEL will go and come, and it's usually a sign of oil in the harness. Have you check your Camshaft sensors for oil in the harness, it should be on a sticky at this point. Many Mercedes mechanics are taking credit for Chassis S-prihady, and a handful of others for troubleshooting the issue (I can't give myself credit. Maybe for being brave and doing the actual repairs myself while troubleshooting with them).
The reason I mentioned it is because I was getting O2 sensor issues coming, and going at year 8, until I fixed the oil in the harness. And I am still rocking the factory sensors at year 12 and 139k miles.
I replaced all 4 camshaft position sensors and 4 solenoids at 30k miles by myself as preventative maintenance. I just checked them again this morning. They are nice and clean, no evidence of leaking. Thank you.
Cool. Check the pins on the ECU with a LED light (phone works). Check every pin in my case I caught early and only had the pins for the O2 sensors with a drop of oil. A Q-tip and contact cleaner resolved the issue.
If you don't find any there you are golden. If you do, clean the harness that plugs into the ECU as well.
Cool. Check the pins on the ECU with a LED light (phone works). Check every pin in my case I caught early and only had the pins for the O2 sensors with a drop of oil. A Q-tip and contact cleaner resolved the issue.
If you don't find any there you are golden. If you do, clean the harness that plugs into the ECU as well.
Thank you for your suggestions. Yes, I checked ECU pins, they all look nice and clean.
At this point, I decided to go ahead and replace the sensors. It's not easy as I thought. Cannot reach the plug-in. My top fingers can reach it but not much I can do about it. There is a metal clip hold it in place. Does any one know how to remove it?
The sensors and the wires don't look bad at all. I know it might be bad inside.
02-16-2024, 02:57 PM
