MPG have been down??

[countryraised]

so, I've had my FU chip a couple months now, put a few thousand miles on it, and my mpg's are about 13.3 running mostly the 65hp DD tune, with rare times on the 120race. stock I would consistently get 15.5mpg.
what tunes should I try for better mileage? other reasons it want down?
One thing, right before the chip, like 1 week, I removed the cat. conv. was pretty sooted. that's the only change.