I did..
Here's how it is. When going downhill, the revs increase because of the camshaft rotating faster (and the cam makes the pistons run quicker).
The O2 sensor tells the ECU how much is beeing sent/used and depending on that, the throttle body is opened.
Basically fuel depends on O2.
Now here's the really funky part, when going downhill in 2nd gear (foot off the throttle) and rpm is at 4k -- More fuel is being burned than when the car is at a stop (neutral), and you press the accelerator and hold it at 4k.
This is because of the load its fighting. But you have to look at it as a negative load. You know? Like going the opposite direction.
Thats it.. I hope I explained it well.
