The STS is going on this weekend but I have my XD-1 wide band hooked up for the last two weeks. When I am cruising at a constant 55 or 60 mph and let off the gas my AF goes up from 14.6, 14.9 to 15, 18, 32 for 1/2 second ,then 20 (flashing which = alarm) and the percent light comes on. 20 is the alarm on the gauge just for now. When the truck gets down to 45mph you feel a hesitation which I think is the converter unlocking and the AF go back to 14.6 , 14.9. I think it is do to the converter putting a negative load on the motor when it is locked.
Any thoughts? Dose any one else do the same thing?

 

when you let off the gas, the motor basically turns into an air pump, that sounds normal to me, I guess.

 

Most late-model vehicles shut the injectors off on decel, so that sounds completely normal to me.

Jody

 

mine does the same thing Darren, dont worry, its fun but also scary at times watching and learning these gauges and how a system affects them.

 

It's called DFCO, deceleration fuel cut-off. You can program it out in the tune if you want, but it's supposed to do that as a fuel saver.

 

Good to hear. Thanks everyone.