Throttle blip shortly after cold start
Here's a plot of data acquired on a laptop from my S15 SR20DE (factory Autech ECU) shortly after startup using the BlaZT Consult cable and DataScan 1.4 software (available from www.BlaZT.biz). You can see how the Aux Air Control (AAC) keeps the engine from returning to fast idle (~1250RPM) for several seconds after the throttle has been closed. It's probably an emissions thing, but has always annoyed me. Nevertheless, this BlaZT kit is a tremendous value at only $100.