I have a 2010 f-350 at 136,000 miles with dpf and egr delete kits and straight stock size exhaust pipe to the muffler. Between 68 and 75 mph at a steady rate of speed the truck will start to surge with no fluctuation that I can see to the boost or rpm gauges. If I gas it or let off the throttle it stops but will continue to have same problem when between those speeds. I'm running a 'Punch-It Performance' tuner I got from Rudy's. The tuner is running level 3 which is+96 HP and +232 ft lbs. No codes. Please help.

 

Hi cwg, welcome to FTE!

I'm sending this one down to the 6.4L forum. Engine-specific issues like that typically get the best response in the engine forums.

 

Thank you I appreciate it

 

Ever get any response on this issue? I am experiencing the same thing with the same tune. I was leaning toward a fuel issue but am wondering if its a tuning issue.

 

And what does the tuner manufacturer have to say about this problem?

 

Havent checked with them yet

 

Monitor the fuel rail pressure and see if it fluctuates along with the surging.