('07 Cobalt LS, 2.2L Ecotec)
Using an OBDlink SX USB adapter and their OBDwiz app on an old laptop, I get the chart below. Engine is at steady (800 rpm?) idle, closed-loop. The displayed data has inflection points about 1/2 second apart. Does this imply that the ECU updates its setting every 1/2 second? Or, is the ECU actually faster, and the apparent timing is just due to limitations in the app/USB capability?
Bonus question: is that amount of variation in (pre-cat) O2 (2nd from top) and intake MAP (bottom trace) reasonable?