2006 Volvo vnl 670 mid 128 pid 411 fmi 0 fault code

I have a 2006 Volvo vnl 670 with a Cummins motor Eaton Fuller autoshift tranny. I just had the exhaust manifold replaced. Now sometimes under a heavy load coming out of tunnel (going up) i get that fault code. Has anyone dealt with this

 

This diagnostic checks the reading of the EGR differential pressure sensor when the EGR valve is open. Since the EGR valve is open, the reading of the EGR differential pressure must be greater than 0. If the ECM detects a reading lower than expected with the EGR valve open, this fault code is logged.


Possible causes of this fault code include:

• A damaged EGR differential pressure sensor.
• A leaking low or high EGR differential pressure tube.
• A stuck closed EGR valve.
• A plugged or restricted EGR cooler.

 

Thanks