P0438 EML ICARSOFT MB2 help request LIVE DATA

[Wenglish]

hello everyone sorry to ask but I’m looking for a little advice please if possible because yesterday I got the dreaded EML light up on my S212 E350 Estate 3.5 CGI Petrol.

The code registered was P0438 CATALYST TEMPERATURE SENSOR CIRCUIT HIGH BANK 2 SENSOR 1 there is nothing online to help me after searching for ages so I just went ahead and ordered new oxygen sensors.

Today I’ve fitted 2 x Brand new Bosch oxygen sensors on each side of the exhaust just before the CAT I also cleared codes etc and as soon as the car gets up to temperature the code appears again P0438 and then the light

Im really stumped on what to do or try next I’ve been told that the ICARSOFT MB2 can do live data readings and it’s especially good for reading the oxygen sensors. I’ve found the section to do this but I have absolutely no idea what I’m looking out for or what the readings should be.

In the last week I’ve had the gearbox serviced and also a engine oil change along with brand new replacement of the rear suspension air bags so I’m really trying to now keep costs down.

Thanks everyone in advance

 

[TheEnd]

There's a specific exhaust gas temperature sensor, separate to the lambda sensors-

One can be seen here, just before the catalytic converter, numbered "130"

Mercedes-Benz EPC. E 212.257 , E STATION WAGON, Market Europe, North America, Japan, Group EXHAUST SYSTEM, Schema of EXHAUST SYSTEM USED ON SIX-CYLINDER GASOLINE VEHICLES.

 

[Wenglish]

There's a specific exhaust gas temperature sensor, separate to the lambda sensors-

One can be seen here, just before the catalytic converter, numbered "130"

Mercedes-Benz EPC. E 212.257 , E STATION WAGON, Market Europe, North America, Japan, Group EXHAUST SYSTEM, Schema of EXHAUST SYSTEM USED ON SIX-CYLINDER GASOLINE VEHICLES.

Thanks mate that’s brilliant would you think that part could be the issue then ? Would make sense wouldn’t it

 

[DSM10000]

As your initial fault code was suggesting a Catalyst temperature sensor and there is one fitted it would be reasonable to assume that is the part causing the error.

I am unsure why you decided to replace both O2 sensors when the fault code did not suggest either let alone both and a quick search for your initial code and fault description did yield quite a few results for that problem?

Look on the bright side, O2 sensors are a common cause of a CEL so you have eliminated that problem for the foreseeable future!

 

[Wenglish]

As your initial fault code was suggesting a Catalyst temperature sensor and there is one fitted it would be reasonable to assume that is the part causing the error.

I am unsure why you decided to replace both O2 sensors when the fault code did not suggest either let alone both and a quick search for your initial code and fault description did yield quite a few results for that problem?

Look on the bright side, O2 sensors are a common cause of a CEL so you have eliminated that problem for the foreseeable future!

Thanks for the reply mate I ’m not a mechanic far from it which from your response I think it’s pretty obvious to how I’ve come across to you by doing what I’ve done.

I simply use the internet and try my best to save money by doing the work myself within reason. The only reason I changed the o2 sensor was because after searching online for help that fault code shows the Possible causes for P0438 as one of these faults = Faulty oxygen sensor / Wiring problems Exhaust air/fuel mixture out of balance Faulty PCM/PCM programming.

Bank 2 sensor 1 again shows the oxygen sensor location hence why I thought it would be this

It also states that the o2 sensors have a livespan of 150k miles mines now on 116k so to save any hassle in the future and the discount I had for the pair it seemed worthwhile at the time to just change both while I was doing the work, And like you said these are common cause for the EML

Anyway thanks for your input and I’ll purchase the new part on Monday and won’t be so silly in future to just buy parts and basically hope for the best. Either way the parts i purchased in the hope of fixing the problem that I didn’t need would still have been cheaper than the average labour charge at a garage so not really the end of the world and it’s another thing on the car that’s now ready for the future.

Thanks again for your reply

 

[DSM10000]

Thanks for the reply mate I ’m not a mechanic far from it which from your response I think it’s pretty obvious to how I’ve come across to you by doing what I’ve done.

I simply use the internet and try my best to save money by doing the work myself within reason. The only reason I changed the o2 sensor was because after searching online for help that fault code shows the Possible causes for P0438 as one of these faults = Faulty oxygen sensor / Wiring problems Exhaust air/fuel mixture out of balance Faulty PCM/PCM programming.

Bank 2 sensor 1 again shows the oxygen sensor location hence why I thought it would be this

It also states that the o2 sensors have a livespan of 150k miles mines now on 116k so to save any hassle in the future and the discount I had for the pair it seemed worthwhile at the time to just change both while I was doing the work, And like you said these are common cause for the EML

Anyway thanks for your input and I’ll purchase the new part on Monday and won’t be so silly in future to just buy parts and basically hope for the best. Either way the parts i purchased in the hope of fixing the problem that I didn’t need would still have been cheaper than the average labour charge at a garage so not really the end of the world and it’s another thing on the car that’s now ready for the future.

Thanks again for your reply

No criticism intended and you have my respect for getting stuck in!

As said ,see the O2 sensor replacements as an insurance policy!

 

[Wenglish]

No criticism intended and you have my respect for getting stuck in!

As said ,see the O2 sensor replacements as an insurance policy!

Thank you