[Gaz64]

Jeff,

Can you look at what settings you have under ECU Programming/Engine/Oxygen Sensor Control Setup?

There are target parameters versus tps (1/100th volt) and "Throttle position to go open loop".
At steady throttle cruise, the oxygen compensation could be pulling fuel out to the point of a light throttle surge.

You can also see this on the AChart data logger.

Naturally don't ask the logger for everything.

I used to look at coolant, air, rpm, tps, O2, O2 compensation, map, accel volume and time, injection volume and time.