[art leong]

Don't know if this will help. But some tuners aren't concerned with low rpms, just horsepower and torque. I brought my car home from a dyno tune a couple of years ago. And it was so rich my eyes were tearing when I put the car in the trailer. I then tried to tune it down low. And made it worse. I went to the track and tried to tune the leave and slowed it up half a second. My plugs would get sooty black driving around the pits. Tried changing plugs, wires etc. No help.
Then I thought about it a while. I was leaving with a 2 step. Which I thought would make it rich, because it wasn't burning fuel in 1/4 of the holes. Then it dawned on me that it is an "Oxygen" sensor not an unburnt fuel sensor. Also I found that below 4000 rpms my wide band O2 sensor in the collector was useless (unless I put a 3' extension on it).
I put in an upstream O2 sensor about 14" from the valve. I use that to tune low rpms. When leaving using the 2 step I just try one thing or another and if it picks up I try a little more till it slows. If it slows right away I go the other way. 99% of the time I have dead hook so no variables there.