what mods or tuning can I do to make my 2005 4x4 xlt automatic more responsive on the throttle. It feels like there is a 1 second lag between pressing the pedal down and the engine actually reacting.

 

Remove any after market Air Cleaners, they "suck" because they do NOT SUCK, lol

Test TPS(throttle position sensor), its a 5volt sensor
TPS is used to give the computer a "heads up" that driver wants to speed up, or slow down
Key on Engine OFF
Should show 0.69 to 0.99volt with throttle closed
4.5v to 4.8volt throttle wide open
Voltage should change instantly with throttle positions

If you have an OBD2 reader then select TPS to monitor changes
17% to 19% throttle closed, 5 volt sensor, so 1 volt is 20%, so just under 20% is correct
% should change instantly when you tap the gas pedal
Should show 90% at Wide Open, 4.5v is 90% of 5volt