"Mods: K&N Filtercharger, LC Eng. Header + Full Exhaust "

lean or rich conditions usually can be traced to the O2 sensor. Where is your O2 sensor mounted in the newer exhaust system, and is it sitting down in the pipe like it was with the stock exhuast or does it mount in one of them bungs that are raised up out of the exhuast stream?

Other than that, tune it to spec. Gap the plugs to .031, ignition timing at 5*BTDC and warm idle speed set to the underhood stickers suggestions. If you arent getting a stored code in the ECU your lean condition isnt as serious as it would seem. Have you tried pulling the codes yet?

~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />