My truck seems to be idling okay. While driving my idle is rough while accelerating and my abs light starts flashing and my speedometer bounces around. These 3 things all started at once and there is not an engine light on...Help!!!!

 

It sounds like the VSS sensor located on top of the rear differential is failing. I just recently replaced mine on an 01 f250 with the same symptoms and all has been well since then.

 

Mine has done this since I loaded my tuner. It never did it before, and only does it under full throttle. Doesn't seem to affect anything and like you said no codes. Would the tuner affect the VSS sensor?

 

chris7678, that definitely sounds like the VSS on the rear differential.

VAXB, that's STRANGE. What engine/year/etc?