I just installed my Flow Tech LT's. I have had the other mods in the sig for awhile now. The car always surged a little at lights after the cam, but not enough to bother me. However now after the LT's the cars RPM's surge up and down so much it damn near dies at every light. I am getting ready to get a tune here pretty soon, but is their anything I can do to fix this problem in the mean time? Thanks.

 

loss of more low end torque maybe, do you have a stall matched to the cam, gears, or a tune for the cam? that will basically rid you of the surge

 

Could you have damaged a spark plug wire during the install? Maybe car is misfiring a bit? Any SES lights?

 

Nope, no SES light

 

The new headers may have had a oil coating inside and when 1st fired up it burned off and corrupted an O2.
Or the headers caused a change in how the O2 is functioning as to its temp and what its reporting so the fuel trims are going from rich to lean on low engine load. This happens if the LTs place the O2 further back then where they belong.
Or the wrong header gasket was used and is leaking.
All the mods added together require a full custom tune for powertrain to function at its best.