My chk engine light came on and the it was the code for low transmission pressure sensor code. I have replaced all sensors and filters in transmission but before I got to 100 miles on it the chk engine light came back on and a lightning bolt light came on as well. the truck goes into a limp mode and will only use 2nd and 4th gear no overdrive. Any ideas. I was told to re flash the computer that it might fix the problem. I also have a H & S racing chip already installed with all the proper modification on it. this just happens every once in a while. I can turn it off and it resets and does fine for a while and then it does it again. Please help.