Advice on O2 sensor Bank 1 sensor 2 on 2016 CLS Shooting Brake 220D

[Westmead Hawk]

To cut a long story short, bought this heart car because I love them and it's under a 90 day warranty.
CEL came on beginning of August. Went straight to garage and diagnostics found 50 codes so they cleared, test drove and the car was fine for another couple of weeks before the dreaded CEL came back on (amber). Didn't drive it again until the garage could see it and this time the codes were more helpful and they diagnosed the fault as the oxygen sensor bank 1 sensor 2 so pre-cat I think.

Now waiting for the dealer warranty to approve the work - part not ordered - I have a feeling this is going to be a wait. What do people think about driving the car in the meantime. Reluctant to do it as it invalidates the warranty but due to go on holiday today - only 75 miles away. OH thinks we should drive the car and it will be fine. I think he's probably right but feel more reluctant since it's a bank 1 sensor.

Any thoughts please? I am thinking the onboard computer has so much data the dealership will know if we drove with the CEL light on post diagnostics it should they check!

 

[onefortheroad]

To cut a long story short, bought this heart car because I love them and it's under a 90 day warranty.
CEL came on beginning of August. Went straight to garage and diagnostics found 50 codes so they cleared, test drove and the car was fine for another couple of weeks before the dreaded CEL came back on (amber). Didn't drive it again until the garage could see it and this time the codes were more helpful and they diagnosed the fault as the oxygen sensor bank 1 sensor 2 so pre-cat I think.

Now waiting for the dealer warranty to approve the work - part not ordered - I have a feeling this is going to be a wait. What do people think about driving the car in the meantime. Reluctant to do it as it invalidates the warranty but due to go on holiday today - only 75 miles away. OH thinks we should drive the car and it will be fine. I think he's probably right but feel more reluctant since it's a bank 1 sensor.

Any thoughts please? I am thinking the onboard computer has so much data the dealership will know if we drove with the CEL light on post diagnostics it should they check!

Tbh the ECU takes over when these sensors fail and default values kick in. Where as if it's working the ECU and MAF work together to give you 100% fuelling . The sensor in question doesn't really do much tbh. I've owned diesels and this sensor was broken but didn't even put the cel on. Changed it at a cost of close to £100 and didn't even notice any difference. I'd not worry about it at all over 75 miles .

 

[Westmead Hawk]

Garage changed the sensor - decided not to drive it in the interim as it was under warranty. Picked the car up yesterday. EML back on today
Is this a thing with these cars?!

 

[rf065]

Garage changed the sensor - decided not to drive it in the interim as it was under warranty. Picked the car up yesterday. EML back on today
Is this a thing with these cars?!

Yes, Euro 6 & diesel = lots of money to fix, simply due to adblue systems which are not fit for purpose. Do a quick search in the 'net, hundreds of companies throughout the UK have sprung up offering "adblue deletes", illegal I know, but how many times are owners expected to fork out thousands for repairs on relatively new, low mileage cars?

 

[Westmead Hawk]

Yes, Euro 6 & diesel = lots of money to fix, simply due to adblue systems which are not fit for purpose. Do a quick search in the 'net, hundreds of companies throughout the UK have sprung up offering "adblue deletes", illegal I know, but how many times are owners expected to fork out thousands for repairs on relatively new, low mileage cars?

I'm usually pretty savvy but adblue has me very confused!

 

[onefortheroad]

I'm usually pretty savvy but adblue has me very confused!

It's basically pigs urine sprayed into the exhaust system ,which helps lower nitrous oxide levels. Roughly 2 new nox sensors fitted £1300 , new ad blue tank when the level sensor breaks £1200 .

 

[ajlsl600]

Absolutely nuts design back shed solution. Should come with 10 Yr makers until and if they ever change from cash cow policy currently in place. UK anyway.
Not popular. But in unlikely even selling my ml is problematic and system fails regrettably I will be doing adblue delete. This design . Is not fit for purpose.

 

[Westmead Hawk]

It's basically pigs urine sprayed into the exhaust system ,which helps lower nitrous oxide levels. Roughly 2 new nox sensors fitted £1300 , new ad blue tank when the level sensor breaks £1200 .

I thought I'd add to this thread - not least because it reminds me what's happened to the car when the next thing goes wrong...
Problems with EML light since O2 sensor replaced in September. Went to main dealer in October and they ran diagnostics, but didn't say anything else needed doing at the time. EML stayed off for the longest time since we had the car - just over a month - then came back on in November. Booked the car in with main dealer since they'd only recently seen it and they could only look at it in January today in fact - needs an MOT at the end of this month so thought may as well do everything at once.

In the interim took it to the local independent German vehicles guy who kindly ran free diagnostics which said a few things incl. NOX sensor. He said he won't touch those jobs because of all the problems with them and I can't say I blame him.

Had a flat battery in the last cold spell and it's thrown a few messages since the DIY jump start including the dreaded AdBlue one and something about Collision Assist and the fancy headlights not working. All those messages have cleared of their own accord on the next start.

MB said today 2 new NOX sensors are needed. I quote 'Upstream And Downstream NOX Sensors required for EML, Also has codes stored for Ad blue system & DPF May need further diag'.

I am not sure I even have a question. Probably here asking for thoughts and prayers since the holy trinity of the emissions hell have been mentioned now

Just hoping to get the NOX done, through the MOT and on we go. Maybe the Indie guy will do AdBlue tanks and DPFs as I'd rather my money went to him. I know so much more (learned the hard way) about the problems with these cars now. I am still hoping for some sunlit uplands with proper usage once we get over this challenge. I mean I'd take 6 months without the EML as a win.

 

[onefortheroad]

I thought I'd add to this thread - not least because it reminds me what's happened to the car when the next thing goes wrong...
Problems with EML light since O2 sensor replaced in September. Went to main dealer in October and they ran diagnostics, but didn't say anything else needed doing at the time. EML stayed off for the longest time since we had the car - just over a month - then came back on in November. Booked the car in with main dealer since they'd only recently seen it and they could only look at it in January today in fact - needs an MOT at the end of this month so thought may as well do everything at once.

In the interim took it to the local independent German vehicles guy who kindly ran free diagnostics which said a few things incl. NOX sensor. He said he won't touch those jobs because of all the problems with them and I can't say I blame him.

Had a flat battery in the last cold spell and it's thrown a few messages since the DIY jump start including the dreaded AdBlue one and something about Collision Assist and the fancy headlights not working. All those messages have cleared of their own accord on the next start.

MB said today 2 new NOX sensors are needed. I quote 'Upstream And Downstream NOX Sensors required for EML, Also has codes stored for Ad blue system & DPF May need further diag'.

I am not sure I even have a question. Probably here asking for thoughts and prayers since the holy trinity of the emissions hell have been mentioned now

Just hoping to get the NOX done, through the MOT and on we go. Maybe the Indie guy will do AdBlue tanks and DPFs as I'd rather my money went to him. I know so much more (learned the hard way) about the problems with these cars now. I am still hoping for some sunlit uplands with proper usage once we get over this challenge. I mean I'd take 6 months without the EML as a win.

You could always pay £250 have a stage one remap and a have an ad blue solution at the same time .

 

[rf065]

You could always pay £250 have a stage one remap and a have an ad blue solution at the same time .

Exactly, because in my experience even after paying a large sum to fix the fault, another ad blue fault will appear anyway with another big bill to look forward too. The whole system is not fit for purpose and ill thought out.

 

[onefortheroad]

Exactly, because in my experience even after paying a large sum to fix the fault, another ad blue fault will appear anyway with another big bill to look forward too. The whole system is not fit for purpose and ill thought out.

No car is worth shelling out stupid money on , especially on something like a daft sensor for nox , when 21 year old Billy Jones down the street is flying about in an over remapped 1.6 Corsa spewing out black smoke for fun and no one says jack s**t.

 

[Westmead Hawk]

Well you've made me laugh ruefully so thank you for that! Will suck this one up and take a view afterwards. I have a loony idea that I can change my numberplates and change my luck. So I'll give that a roll of the dice too...

 

[Westmead Hawk]

You could always pay £250 have a stage one remap and a have an ad blue solution at the same time .

How do you set about finding someone to do this? And then do you become an untouchable at the main dealer forever? Like is it reverse engineering the software updates they do... I must admit the whole thing is an eye-opener.

 

[Blobcat]

How do you set about finding someone to do this? And then do you become an untouchable at the main dealer forever? Like is it reverse engineering the software updates they do... I must admit the whole thing is an eye-opener.

You leave yourself open to future costs… having to pay to fix the emissions system if for example trade it to a garage and it’s found that the AdBlue or DPF are no longer working. Your car is also not insured if the insurance company were to find out…
Just because someone else is breaking the law doesn’t make it right. I agree completely that the system as designed and implemented isn’t suitable - and that’s all Euro 6 not just Mercedes.

Fix it, sell it, get a V6 or V8 petrol whilst you still can and enjoy it.

 

[onefortheroad]

How do you set about finding someone to do this? And then do you become an untouchable at the main dealer forever? Like is it reverse engineering the software updates they do... I must admit the whole thing is an eye-opener.

Look on Facebook for such a service , any tuning place that does remaps now offer ad blue solutions.

From the amount of cars being modded in a few years time you'd be hard pushed to find one with working nox and ad blu. One tuner even admits to doing work for a mercedes main dealership.

 

[alexanderfoti]

Chose a reputable company rather than a faecbook jobby that comes along with unknown files! I have to rectify a lot of damage done by crappy tuners and people who don't know what they are doing.

 

[Blobcat]

Chose a reputable company rather than a faecbook jobby that comes along with unknown files! I have to rectify a lot of damage done by crappy tuners and people who don't know what they are doing.

Keeps you in business though... every cloud and all that...

 

[alexanderfoti]

Well yes and no. Often we will be tasked with fixing a problem, only for owner to not inform us somebody has fiddled with the software.

It adds another facet to diagnosis for sure

 

[Blobcat]

Well yes and no. Often we will be tasked with fixing a problem, only for owner to not inform us somebody has fiddled with the software.

It adds another facet to diagnosis for sure

Yes, I can see that it could make diagnosis much more challenging not knowing the full story. I can also foresee some “debate” with said owner about the issue which could make things difficult as well

 

[malcolm E53 AMG]

To be honest I’d sell the car and move onto a petrol or backtrack to an EU5 cdi version of the CLS there will still be some low mileage well cared for examples around. My E350cdi estate will be my last diesel when it goes it will be changed for a petrol version I’ve already done this with our other car. EVs - not for me at the moment too expensive and the infrastructure isn’t there yet