Just installed an FIPK on my 05 5.4L and am seeing and hearing power gains, but am not sold that I am seeing economy gains. Yes, I got the heavy foot X out of the way with the first 1/4 tank and now am seeing the MPG guage dropping faster than normal when I drive conservatively. Do I need to reschedule the computer with something like a Superchip device? Also, disconnected the negative cable on the battery after speaking to a tech rep @ K&N, hoping that would reset the computer, but just read something else in a forum that said to disconnect the positive instead.

 

OK first, disconnecting the pos or neg from the battery has the same result, power is cut to everything. It is recommended to disconnect the negative because there is less chance of it sparking and exploding the battery. After you've cleared the PCM it will take about 1 to 2 tank fulls before the computer adjusts for the new air/fuel mixture caused by the FIPK.

I have the FIPK as well. Throttle response increased a little, but I noticed no gain in MPG. I have since re-flashed my PCM with a custom tune and replaced my exhaust with Magnaflow SI/DO. All 3 mods together boosted me about 1.5 MPG (from 13.5 to 15) and clearly increased my throttle response.

 

Dano, Thanks. Expected a little better MPG, but am getting better than 17 now. Will be looking to upgrade the exhaust in the future.
bambi!

 

Your probably not seeing gains MPG wise because you probably have a heavier foot right now, if ya now what i mean. Wait a while and it will go down. Exhaust wise, its not gonna do much for performance, you should get an exhaust for sound, not for performance

 

yeah sounds like it just needs to get used to it all, after the first week it should work great.