Some help for a new member fuel mileage gone to hell

[Mclinko]

Okay so I have a 2008 Tahoe LS Police Model, around 85000 miles! I picked up a Volant cold air intake, with ram air tube, and throttle body spacer. But now it seems my gas mileage has gone to hell, my throttle response sucks! And when approcing a small hill it seems if I was towing another vehicle behind me I end up having to put my foot in it to maintain speed up the hill.
It's so bad I almost think of putting the stock box back on! Or would buying a programmer help this issue like bullydog?!?
I must add that I have no check engine light or code,

 

[jrplz]

Okay so I have a 2008 Tahoe LS Police Model, around 85000 miles! I picked up a Volant cold air intake, with ram air tube, and throttle body spacer. But now it seems my gas mileage has gone to hell, my throttle response sucks! And when approcing a small hill it seems if I was towing another vehicle behind me I end up having to put my foot in it to maintain speed up the hill.
It's so bad I almost think of putting the stock box back on! Or would buying a programmer help this issue like bullydog?!?
I must add that I have no check engine light or code,

Old post but here it goes did you disconnecting your battery so the computer does a relearn ? Google (computer relearn procedures) some people will tell you no not needed But IMO and from personatly doing this on My Tahoe I could tell you it worked ! after the volant install on my truck it felt like I was pulling a semi but I did the relearn and it worked good for me.

AGAIN !!!! IMO good luck to you