2005 Ford F350 6.0 diesel. Why is it so sluggish off the line? The turbo doesn't fully spool up until well into 2nd gear and then it's less than 20psi.
It's been bulletproofed complete with head gaskets and ARP studs. 77,000 miles. All the specs ICP, IPR etc read within tolerances. The back pressure is a little elevated, but not terrible. I've replaced the MAP sensor, and I tried disconnecting the catalytic converter and the back pressure went down, but the lag remains. Can anyone help?
