I always thought it seemed wrong that the procedure says to do the static check of moving the airflow sensor plate to get 10 percent reading. If not check throttle valve switch. Then open throttle should show 20percent if not check airflow sensor potentiometer. It seems as though these two are mixed up. I would think that the airflow plate check should coincide with check the airflow sensor potentiometer and the throttle check should go with the throttle valve switch check. I however am not even close to being an expert on this . Just seems strange. I also found that if I set lambda to get a 0 center point for eha current I do not get 50 percent lambda. I think it was around 60percent. I set it slightly rich from there because idle was a little rough and I would occasionally get a code 17(oxygen sensor signal problem). My car has 270000 miles on it so my tolerance for perfect running is not as high as when it had 80000 miles on it. My car is a 91 300e