Cat Power and MPG?

Have a 99 3406E rated at 550, 13 spd, 3.58s on tall 24.5, its an IH 9300, pull a stepdeck. Have done a few things in the quest for a bit more power and mpg. Boost wire. Then fuel temp wire, which I noticed a real increase in power and mpg up easy .3 and more. Then yanked the under bunk muffler and put on a Grandrock 'performance' replacement. Noticed higher pyro temps with that muffler so replaced it with a resonator only. Pyro temps back down.

It seems as power and mpg are down in comparison to when I added the fuel temp wire. Now, just changed injector codes to 5232. Did not really notice a power increase. Boost is up a bit though. Saw 32 psi. Goes to 28 on the cruise. This first run I'm running with only about 15000# on the deck and not a tall load. Power hard to compare with a light load, but, just doesnt seem as strong as it should, or as it did back when doing the fuel wire. And, fuel mileage seems horrible for being this light. Under 6 mpg, running from IL to Amarillo, TX. Had some wind to run into, but still a very easy load! Was getting mid 6's with around 35k# loads in most areas. It was in mid November when I did the fuel wire, so a little warmer weather. But does the cold weather and winter fuel kill that much mpg and power too? What change in mpg is usually noticed with injector codes?

Seems power and mileage both are lacking. This truck never really felt as strong as it should to begin with either, before changing anything. Also, had the overhaed done in Nov. too. Everything seems in correct working order and it seems to run fine. Boost good. Fuel pressure good. Just noticed on the engine tag, FLS/FTS settings of -1/ -4. Looking for ideas and insight please. Really appreciate any help.

 

This one is a 1LW. If the actuator is not working right will boost still be fine?
Thanks DDS

 

My boost is still up like it has been. A little higher with the 5232 codes in. So, would the actuator be a possibilty?

 

If there is a restriction in one of the fuel lines, will fuel pressure still read ok? And would boost still come up ok if fuel was actually being restricted? Power and mileage sure seem to be going away on this thing. Seems to run ok though, no misses or anything. Any help is sure appreciated.