Hello again! A few years ago my Trailblazer would go at the normal 6,000 RPMs at idel, but the oil gauge would go down to zero, causing the car to stall at red lights. I was having to keep the car reved manually to avoid the stall. So two summers ago I sent the PCM to the place in North Carolina asking them to set the RPMs at 9,000. Since then the oil pressure stays good. But I've been fighting with a P0171 code for a while now, trying all different fixes, and am wondering now if the higher RPM at idle setting could be causing that code. Thanks for your help!