Yesterday I installed a set of Nightrider's O2 Sensor Inline Enhancement Device's on my 2007 Ultra. It only took 15 minutes to plug them in. These are resistors that fool the Delphi ECM into thinking its running at a 14.7 fuel mixture when in reality its running at 14.2. What a difference that .5 fuel mixture richening makes! It lowers the heat coming off the rear cylinder 100 degrees, measured at the spark plug area! After installing this $70.00 kit, I couldn't be happier. I took it out for a 250 mile ride yesterday after the installation and the fuel mileage actually went up! Before the kit installation, I was averaging 40/41 MPG. After the kit was installed, and filling up twice to make sure, I kicked out 45 MPG. It no longer goes into the parade mode either. (Thats where the idle falls to 900/950 RPM). At a train crossing I just let it idle, and it never went below 1000 RPM's. The heat wasn't too bad either. Don't get me wrong, its an air cooled engine and there is still heat, but no where near as bad as before the kit. the temp was only in the mid 60tys too, but before the heat coming off the rear jug was really bad, even in 60 degree weather. I can uninstall this kit is less than 15 minutes and take the bike in for warranty work with the dealer non the wiser! A big plus when you shell out for the extended warranty. If your having heat issues and want to keep the bike stock, like I do, give this kit a try. The kit is even on sale! They won't let me post the URL on this site, so Google "nightrider.com".