I have a question about O2 readings on my Scanmaster. Gettting some knock on my SM as I rev thru 2nd gear. If I hit recall on my SM can I use the readings to tell if I'm too lean? Or do I have to make a full pass? I ask this because when I hit the recall button it shows high 600's, 698 to be exact. This happens as I go through 2nd and any detonation I get out of the throttle. Will try an get a 3rd gear reading once I get a brake tag on the car.