98 EB 5.4 4x4 - replaced CATs, now speedo inop

[CTulloss]

Hey all,
So as the title says, I replaced all 4 cats today to complete my exhaust system. It runs/idles great. I went to give it a test drive around the neighborhood, and noticed the speedo isn't working, and it holds gears until about 3-3.5k rpms. I assumed at first that maybe I pinched a wire or something during the mid-pipe install, but I would think that would give me some codes. I've got nothing. Ideas?
Thanks

 

[Thermo]

CT, crawl back under the truck on the driver's side. Look back where the driveshaft meets the tranny. If you look more up on the upper half of the tranny tail piece, you will see a small black sensor sticking out of the tail piece. This is your VSS Gear (aka, speedo gear). Is the plug still connected? If it is, then follow that wiring back towards the motor doing an inspection of the wiring. if you see damage to the wiring, that is where your problem lies. Odds are, you will find that someone was not careful with a torch and got some wiring a little too warm if that is the case. May be that the wiring was on the backside of a heat shield and the torch heated up the heat shield too much.