I have struggled with a rough idle when hot issue on my '05 wee for a while(2 months tinkering on weekends trying to pinpoint the cause). When it's all the way warmed up the idle will drop a few hundred RPMs. I think I have finally figured it out. My IAP output voltage goes nutty when the bike gets all the way warmed up and is at idle. When I take off from a stop under those conditions it sputters and tries to stall. It seems to be OK once the RPMs get above 3,000-3,500. The IAP sensor is crazy expensive (IMO) at $265 so I'm wondering if there is anyway to eliminate it entirely? If I disconnect the vacuum line the bike runs much better. I attached a marinade syringe with a vacuum line to the sensor and as soon as I apply a vacuum to it the idle goes way down and gets rough. I don't want to unplug the sensor because i get an F1 error on the display and I'm not sure how bad it might be for the engine if I cap off the vacuum line and leave it disconnected from the sensor.