I found the problem the dash started saying speed limiter so the scan tool said trans was in reverse while in drive and reverse lights would come on in drive im thinking that there's a speed limiter for reverse 30mph im gonna install a nsbu switch and see what happens thanks
Im working on a 07 work horse with a 6.0l gm gas with a 4l80e trans i have a o2 sensor code
Truck accelerates good shifts to 2nd then when it hits 30 mph its like it hits a speed limiter not sure where to go any suggestions