I recently installed on a 2005 Dodge 1/2 ton 4x4 5.7 Hemi:

K&N cold air intake
Hedman tight tubes headers
Hamburgers throttle body spacer plate
Since the installation I am experiencing a 5 mpg loss over stock.
Any information or advice would be greatly appreciated.

 

Are you driving more aggressively now?

 

No. Driving at 55 mph its getting 13 mpg instead of the 18 mpg it was getting stock

 

With my 05 4x4 i have not done any better than 13. Even when the truck was completely stock.

 

my totally stock o5 hemi 4x4 gets 14.7 with the cruise on and about 11.7 in town if I keep my foot out of it-not very good but I still love my rumblebee

 

If I had to guess, I'd say the TB spacer combined with the CAI is freaking your computer out. Basically, it's expecting a certain air/fuel ratio as a baseline, but with the recent additions you have shifted that baseline, so the calculations are a bit off. Either give the computer time to readjust itself or do a hard reset to force it to relearn the settings.

The best way to reset the ECU is take in to the dealership and have them do it. Failing that, you can try to play the guessing game with disconnecting the battery, waiting, and reconnecting it back up. The amount of time it takes to clear the memory varies by vehicle and model year.

Alternatively, the following procedure works for most cars/trucks: *EDIT* this is a Nissan reset procedure .. may or may not work on a Dodge

ECU Resetting Procedures

Timing is extremely critical. If it is NOT DONE within the specify time, the ECU will not reset and the Check Engine Light (CEL) will continue to remain ON. A stop watch or an analog clock with a second’s needle will be useful.

Operations Procedures
[ol][*]Confirm that accelerator pedal is fully released, turn ignition switch “ON� and wait 3 seconds. [*]Repeat the following steps (2a and 2b) procedures quickly five times within 5 seconds. [ol][*]Fully depress the accelerator pedal (HARD). [*]Fully release the accelerator pedal. [/ol][*]Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the CEL starts blinking. [*]Fully release the accelerator pedal (while the CEL is still blinking) [*]Wait about 10 second. [*]Fully depress the accelerator pedal and keep it for more than 10 seconds. [*]Fully release the accelerator pedal (The CEL light will continue to blink). [*]Turn ignition switch to “OFF� position and now you can start the car. The CEL light should be gone. [*]If the CEL light continues to remain ON, repeat the above steps. Timing is EXTREMELY critical to resetting the ECU. [/ol]

 

Check for damage to O2 sensor wiring,
or the O2 sensor itself
which can be 'poisoned' by something as simple
as the wrong sealant used to make or improve a gasket.