I have an 03 XLT Epedition. The boot on the brake booster is ripped so I have vacuum leak this will be replaced this week. at the same time I started toget bucking and power loss at highway speeds to the point I had to pull over shut off the truck and start it back up again this would allieviate the problem for a little while. I am thinking the throttle posistion sensor but it seems to happen at the same speeds all the time and now I am wondering if I don't have a tranny problem instead because the problem happens when the gears are shifting notably at 44, 58 and 74 mph I don't know if those are the shift points but it happens at those speeds almost every time. I have even played with the OD vs. D with the same results. I can do this work myself but I am looking for a starting point to chase this down. Any help would be greatly appreciated. Also the CEL light came on probably from the vacuum leak and the last time I pulled over to reset the truck after the power problems the battery light came on.

 

Well I replaced the TPS and all is well again amazing how a $30 part can bring your truck down. Now the only thing is I lost my cruise control? chasing my tail !!

 

Thanks for the update..

If you'd like the schematic to start you search and check for power distribution/circuit continuity ect, let me know..