ABS and Brake lights Chevy S-10

[kitcchr]

I have a 03 chevy s-10 with 125000 miles. The truck recently had the front brakes replaced (rotors and pads) and the rear brakes inspected (they where fine). About a week after the brake job, the ABS light and Braking brake light came on. The car drove fine under 60 mph but had periods where it drove differently at highway speeds. The truck would randomly rev up into the 7-8 rpm when accelerating and not want to accelerate. It also vibrated more when this was happening. I took it back to where I had the brakes replaced and they found no issues with the brakes but found computer codes suggesting the rear speed sensor. They recommended taking it to another shop because they did not handle these repairs. I took it to another repair shop (transmission shop/brake shop) and they had the truck for a week and could not find any issue. The lights did come on, but the speed sensor was measuring at the factory settings. They recommended that I take it to the dealer because they could not determine the problem. The dealer has had the car several times over the last 2 weeks but has been unable to pinpoint the issue and says they can not duplicate the problem. I know that they have driven the car because the gas was basically empty when I received it back and the mileage was different. Could this be a computer issue? I don’t really know where to go from here and I can’t believe that no car repair shop can find the problem.