04 6.0, all stock except for EGR delete

Installed EGR delete and removed the EGR throttle plate. Prior to the EGR delete I was getting 25-26 psi max boost, after I am getting 22-23. CEL is not on but I am getting an insufficient EGR flow fault. Have double checked all of the connections and can't find any sign of a leak.

Boost is being measured via torque pro and an autometer gauge tapped at the intake elbow, they are very close.

Could the fault code be affecting max boost? Another theory is that the removal of the EGR throttle plate changed the air flow causing the gauge to read a lower value. Thoughts ?

 

You need a tuner to deal with the codes.

Boost could be with the changes, or it could be a few things. Check the up pipe to turbo connection, make sure it's on fully. Also make sure the CAC tubes are on properly and that the CAC boot at the turbo isn't cracked. Pull it, clean it and double check it.

 

doesn't an egr delete lower back pressure? That would mean lower boost numbers but better airflow.... at least how I see it. My EGR is deleted, I see 25-27lbs on hard throttle.

Did you leave the EGR valve plugged in and just laying there? It's not seeing flow because there isn't any to sense and for the code to be cleared, you need a tuner, that code won't set a CEL in the 03/04 truck.

Your fan won't run right either if the valve is unplugged.

 

Thanks for the replies, i'll check the connections again.

The valve is still in place and plugged in, the computer is doing what it is supposed to do and detecting insufficient flow. I read that unplugging the EGR valve could cause problems with fan operation and I seem to recall that people had reported lower boost with the EGR unplugged. While my valve ISN'T unplugged the computer is still aware that the EGR system isnt functioning so I was wondering if that could cause the lower boost.

What should the VGT duty cycle be at WOT?

 

I would think that wouldn't change after EGR delete. 15-85% without a tune. Mines tuned and I see about 77% at idle, 45-55% or so going down the road and under 20% when stomping on it.