Exhaust pressure sensor OM651

[sautah]

I’ve been chasing a weird issue where my 250cdi 2011 C207 has been changing gears that in my opinion was too soon. What I mean is it was overly keen to keep the revs low.

Eventually the car threw a P0471 error relating to the exhaust pressure sensor located near the rear of the egr valve.

Looking at the live data it seemed ok to my limited knowledge but as I can’t find anything else that could explain it ( I understand a split boost hose could trigger this somehow) I bit rhe bullet and have fitted a new one.
Part number for a new one is PMA0091535128

Now oddly the one that came out is nothing like this new part number so perhaps it’s either the wrong part fitted or just a very old part number

The car now appears to shift gears much smoother at a much more sensible time and doesnt hang onto gears / labour the engine like it was

 

[OneForTheRoad]

Where did you buy from ?

 

[sautah]

Mercedes Newcastle

 

[sautah]

Where did you buy from ?

Mercedes Newcastle

 

[OneForTheRoad]

Part number will be A0091535128. It's the latest version of the part available.

Your car will of been dropping into limp home mode with a faulty sensor , that's why the gears don't rev up. There's no turbo boost .

 

[Supernoodle]

If you looked at the live data before, did you make a recording and check the values after the change?

 

[sautah]

Part number will be A0091535128. It's the latest version of the part available.

Your car will have been dropping into limp home mode with a faulty sensor , that's why the gears don't rev up. There's no turbo boost .

Correct. That is the part I bought

 

[sautah]

If you looked at the live data before, did you make a recording and check the values after the change?

I did look at live data as mentioned above. The reading at idle on the old one was higher across the board from engine off to idle to 3000rpm where I decided to compare

 

[sautah]

After doing some decent miles today the whole car feels back to its normal heath. Power wise and gear change wise.

 

[benih]

Part number will be A0091535128. It's the latest version of the part available.

Your car will of been dropping into limp home mode with a faulty sensor , that's why the gears don't rev up. There's no turbo boost .

I also had a fault on my car about the back pressure sensor and I just replaced it with the exact part from mercedes and the car still got into limp mode. Once i turn off the engine and then back on again then it is fine for a while. Then it can get into limp mode. Can someone help?

 

[sautah]

In my case this sensor was part of the reason for no regens / dpf fill level 400%

So if you’ve not cleared the fault codes and not run the car whilst monitoring to watch the regen complete you’ll keep having issues.

As long as that’s the issue of course. Lots of things can put the car into limp mode / fail regens. Easy to see with a decent diagnosis machine / dongle etc.

 

[OneForTheRoad]

I also had a fault on my car about the back pressure sensor and I just replaced it with the exact part from mercedes and the car still got into limp mode. Once i turn off the engine and then back on again then it is fine for a while. Then it can get into limp mode. Can someone help?

Fault codes ? Live data for dpf pressure sensor ?