help with 2096 cel code

[carmos]

hi all,i have installed some dnask headers and ever since i get this cel code 2096..the code reader i bought says delay time in bank 1 o2 sensor..i kept the front o2sensors installed in the headers and the rear ones were extended and installed just behind the secondary cats..at 1st the cel would come on every 250 miles or so..after i got the giac ecu upgrade it started coming on every 120 to 130 miles...now it comes on every 50 to 60miles...any thoughts or help would be great thanks..

p.s. my gas milage has also droped about 4 to 5 miles a gallon..when driving normally not racing...