2010 silverado dont have the power it should

[Sliverado102017]

I have 2010 silverado 1500 4.8 it do t have the power it should on hills and when hauling a trailer i changed maf,fuel pump,spark plugs coils and wires.i even bought a bully dog tuner and does nothing any ideas im about ready to pull my hair out 

[WilliamBos]

Before you unloaded the parts cannon did you do a diagnostic scan?  
Did you use an OEM fuel pump and MAF?  The 4.8 is an enemic slug when towing due to GM’s torque management.

 

I had an 04 Sierra 5.3 and traded that off for an 11 Sierra 4.8 - the difference was noticeable, the 5.3 was superior in every way.

[Mikebtte]

Ya, they all are sluggish. What gears does it have? 3:08 is kind of an issue and if you have a 6 speed a 3:42 helps.. GM was not worried about towing as much as getting that MPG rating.

Also a throttle controller helps a bunch, that throttle body could always use some real good tuning. They are very slow to respond.

[swathdiver]

9 hours ago, Sliverado102017 said:

I have 2010 silverado 1500 4.8 it do t have the power it should on hills and when hauling a trailer i changed maf,fuel pump,spark plugs coils and wires.i even bought a bully dog tuner and does nothing any ideas im about ready to pull my hair out 

Those 4.8s do not have big towing numbers anyway.  4-speed trans, highway gearing and what 300 ftlbs of torque?

 

The 4x4s have 3.42 gears and are rated between 5500-6000 pounds depending on the cab and bed.  The RWDs with 3.23s are rated 4700-5200 pounds and the RWD 3.73 geared trucks are rated for 6700-7200 pounds.