What activates the air injection pump and what deactivates it? I've got a situation where upon starting the engine, the air pump runs longer than normal, 90-120 sec, vs 30 secs. In addition, which I think has caused a couple of P0411 CEL the past couple weeks, when the air pump comes on the second time around (after about 5 min of drive time) it has been abruptly (i.e., not smoothly) shutting off after 1 or 1.5 sec versus 5 secs or so (and shutting off smoothly). Anybody know what this might indicate? Some kind of switchover problem, O2 sensor problem, or air injection pump problem? Thanks.