Volvo D12 worse MPG

I would not unplug the EGR on a Volvo engine. I'm not very familiar with the d12 but I have a D16 and it's a bad idea. The excess exhaust pressure can cause you to blow your valve stem seals, and cause the turbo to overwork, you will here it wind up when it's supposed to EGR. Also your engine will de-rate when it throws the mid 128 code for the EGR. I don't believe you can flash a Volvo ECM either, I believe you have to have a connection to Volvo in order to alter the ECM. I can tell you what worked for me: Check for exhaust manifold leaks, check for EGR system leaks on all tubing (allot of dealerships do not change the gaskets when servicing when they should), check all piping around the turbo (again checking o-ring gaskets and such), have one person step on the fuel and another watching the EGR valve/valves and make sure they are working after the throttle is released, keep rpms around 1400(mine runs 59mph 1400 or 68mph 1400), make sure there are no 128 codes for the turbo actuator, make sure no fuel filter codes(sometimes the overflow valve creates a fuel filter code). I can list more if this don't help.
My fuel economy pulling a flatbed is as follows: Empty 8.2-9.3
light load mid 7.2-7.9
heavy load 6.3-6.8

Allot depends on wind with a Volvo & again with a D16 keeping it at 1400 is critical. Numbers are better if I run at the 58-59mph for the obvious.

 

There is a way to unplug the EGR and get no codes but in order to relieve some exhaust pressure you have to make a couple pretty big alterations. Again, mine is a D16 not a D12 so yours may be a little different.

 

i have a proablem with my brake lights they dont came on utul i push realy hart on the the brake pedal i bellive in the swich undernite the breke pedel .thanks a lot in adevence.

 

Flying j still selling bad fuel? Its pilot now

Yesterday I made 1200 miles its cover all fuel
80 mph half way.
55 - brrrrrr too slow.

Yes it 5mpg on isx does not matter loaded or not
But depends on wind.

 

Can be switch on pedal or air pressure activated switch or both.