V50 Engine 2.0D : Poor fuel economy, poor starting and shaking on low rpms

[Nikeng]

As the title suggests i have some problems with my volvo.

So far i've replaced the right turbo control valve, the crankshaft and cam position sensors and cleaned the throttle body. (i have a new one of those on the way, but i dont think that will solve the shakes, only the starting issue.)

The dpf and egr was replaced about 2k miles ago, aswell as eyolys fluid topped off by the previous owner.

I have only owned the car for about a month and it has been this way since i bought it. (got a good deal thinking this would be an easy fix)

with the torque app i get the fault code p1412 "egr differential Pressure Sensor Signal too Low". i thought this might be the dpf pressure sensor ,since torque only gives generic codes, so i took it out and tried drying it out with an heat gun and then leaving it overnight on a radiator. no difference.
Is it possible that the sensor is clogged? if so can i clean it with some contact cleaner?

I recently had to do a longer drive of about 300 miles of non stop highway. After about 250 miles i got a message that read "engine service required" that dissapeared after a restart.

I'm no stranger to working on cars, but since this is my first volvo and first diesel i thought i would try to get an second opinion from someone who knows a bit about these cars.

[Lightguard]

Try to clean your MAF too, it can be related to poor economy and low rpm shaking. When was your air/fuel filter replaced?

[Nikeng]

Originally Posted by Lightguard

Try to clean your MAF too, it can be related to poor economy and low rpm shaking. When was your air/fuel filter replaced?

I forgot to mention but i replaced the filter and o-ring a week ago along with the air filter. also tried to run without maf connected. made no difference.

[x DTR x]

I believe if the car still runs when you disconnect the maf then the maf is faulty? The engine should cut out. Someone will correct me if wrong!

[Lightguard]

It is definitely suspicious if disconnecting the MAF doesn't make any difference.

Originally Posted by x DTR x

I believe if the car still runs when you disconnect the maf then the maf is faulty? The engine should cut out. Someone will correct me if wrong!

As far as i know the ecu uses hard-coded values in case of missing sensors, in this case i guess it simply assumes a fixed amount of air intake.

[Nikeng]

Originally Posted by x DTR x

I believe if the car still runs when you disconnect the maf then the maf is faulty? The engine should cut out. Someone will correct me if wrong!

Disconnected with the engine off, only ,made a message pop up on the dash. not even a check engine light.

Took it off last night and cleaned it off with some contact cleaner and isopropyl alcohol and left it to dry inside overnight. will report back with results. Not very hopeful though.

[Lightguard]

Btw. is the temperature shown by the dash correct?

[Nikeng]

So i might have solved my own problem.
Even though it was the first thing i tried, i swapped the egr/ glow plug/tcv fuse (nr 56) with another 15 amp. not sure if it was that or the maf/dpf sensor cleaning that did it, but the p1412 code is now a pending fault vs a current one. the next few days will show if that did it or i have more problems.

[Nikeng]

Originally Posted by Lightguard

Btw. is the temperature shown by the dash correct?

Seems to be, yeah. Why?

[Lightguard]

I was just trying to figure out the reason of the poor starting.