Hi Eugene,
Thye ECU stays on closed loop with the lambda most of the time which means it should run a good AFR.
If i remember correctly, your the guy that came down to us and we didnt want to fit the ECU due to cam and follower noises?? If so did you get this rectified?? May be the problem if there is one or may be a sensor problem, As the guys have said give us a call. Unless we hear about these things, theres not much we can do. If the car is running rich im confident its not the ECU. (Give us a bell)
Andy