Yeh, the duty cycle is just outside of the 10% window between idle and 2500 rpm, just a litte bit out on the rich side. Driveability is great, but gas mileage isn't very good, so I'm looking for anything that may legitamately help my mileage. I just want to get it within the 10% spec and see if I can improve my mileage without hurting the driveability. BTW, car has 187K miles and the idle has never been adjusted. Last emissions test here in Florida (before they stopped doing it here a few years ago) it passed barely, and was on the high side of CO at idle. I think I just need a little tweek. Can I just split the top of the lambda tower and pry out the ball?

Thanks