I have a 2001 V6 coupe. I have installed the following:

Cold-air Intake
Shorty Headers
Cat-back dual exhaust
3.73 Ring/pinion gears
Underdrive pulley

After all of that, I have lost an appreciable amount of power at the low end. It really lugs down at 30-45 mph (sometimes I have to drive the speed limit after all )

I have the Diablo Predator flash tuner and can adjust certain things:

Dual timing adjustment points (2000-4000 RPM / 4000-7000 RPM)
Timing table (+10% / -40%)
Dual fuel adjustment points (2000-4000 RPM / 4000-7000 RPM)
Fuel table (+40% / -15%)
Idle (+/- 20%)
On/Off switch for Traction Control
Raise Speed Limiter
Rev Limiter
Re-Calibrate Speedometer for Gear and Tire Size Changes
WOT Shift Pressure
Part throttle shift firmness
RPM Shift Points
Torque Modulation (for better shift feel)
Cooling Fan ON/OFF Temperatures
Rear Oxygen sensor disable (use for off-road vehicles only)
Disable EGR (use for off-road vehicles only)

Being a rank amateur, I have no idea which of these should be adjusted and in which direction to correct for the loss of low end (or even if suuch a thing is possible with the Predator).

Any and all help will be appreciated.

Curtis

 

Unless you know what you're doing, I recommend sticking with the preprogrammed performance tune that comes with the Predator. This should improve your power across the RPM range. If you install the performance tune, make sure you're running premium gas (this is in the manual, so no surprise here).

You can also use it to adjust your speedometer. Set the axle ratio to 3.7 for your 3.73 gears.

Do you have an auto trans? If so, you can play around with the shift settings. Obviously, these have no effect if you have a manual tranny.

 

Maybe with the headers and exaust not enough back pressure? That would explain the now low end.