Ideal DPF pressure
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Joined: Aug 2021
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2008 E320 Bluetec, 1987 190e 2.6, 2007 CL600
Ideal DPF pressure
Does anyone know what values a functioning b28/8 differential dpf pressure sensor should read at idle, running and boosting at 3000rpm?
I have negative value at idle and at about 3000rpm it reads over 4500hpa
I have negative value at idle and at about 3000rpm it reads over 4500hpa
Negative at idle is normal, and at the top end some 40-50 hPa is somewhat normal (based on Euro 6 truck engines). 4500 hPa sounds insanely high! Is there anything abnormal with the car besides the high hPa reading?
Thread Starter
Senior Member




Joined: Aug 2021
Posts: 335
Likes: 33
2008 E320 Bluetec, 1987 190e 2.6, 2007 CL600
My mistake, it’s -7 hpa while not running just key in on position, at idle it is about 68 and it’s reaching 450 hPa not 4500, when I hit about 3000rpm. This is triggering limp mode but no other drivability issues if I baby it and stay under 3000rpm.
Occasionally throws dpf code for ash or high backpressure, but I had dpf refurbished (was completely blocked) last year and am still getting 35-40mpg on highway. I think it’s just this glitchy sensor or left over ash in the lines
Occasionally throws dpf code for ash or high backpressure, but I had dpf refurbished (was completely blocked) last year and am still getting 35-40mpg on highway. I think it’s just this glitchy sensor or left over ash in the lines
Last edited by BetterDaze; Jun 1, 2022 at 04:52 PM.


