On the lookout
 

for someone in the ecu tuning community that can make some changes to my car so it won't do that idle-up crap at low speeds. Bothers the heck out of me that I could be getting 50% better mileage during those times of low speed coasting!

Maybe cutting out the VSS signal via a switch on the dash would fool the ECM into thinking the car is stationary?

I have a few questions.
1. Is the car in drive on neutral?
2. Are you pressing the gas at all?
3. Is it the same going uphill, down hill, and on flat ground?
4. What speeds is it doing this?

I've considered that, but I 'think' this may be able to help the OP >

Speedo Corrector MkII Kit - Jaycar Electronics

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1. Neutral on a manual tranny.
2. No
3. Yes
4. From 1-30 mph it does it.

My guess is that it is doing this to prevent stalling if the driver quickly changes load. If you leave in in neutral for a little bit does it return to stopped idle speeds?

Do you have a scan-gauge or something similar?
Instead of shifting to neutral if you are not stopping try shifting up and hold a low RPM.