I just replaced the engine and trans in my hatch, all the wire connections are hooked up, the idiot lights on the cluster come on but the speedo doesn't work...not sure about the temp or fuel cuz I haven't driven it for long since the swap. I need to get a cat-back installed, I just have the header and b-pipe on now...that wouldn't cause the speedo not to work tho right?

 

if the speedo worked before the swap i would check the vss (aka speed sensor). maybe you forgot to plug it up, or it's bad, or damaged. the combination of that and the cat less exhaust you have will trigger the CEL.

 

I have no CEL either? Don't know if the VSS worked as I bought the car with a blown headgasket. I did try switching the VSS from the original trans and it didn't work...one is deeper than the other though.

 

Well, first I'd hunt down a complete schematic for the IPC circuits and make a list of the associated components between the speedo and the VSS. Then you can employ a basic process of elimination (assuming you know your way around electrical diagnosis).

You can start by painstakingly checking the wiring and connectors for shorts or opens, or you could get a replacement VSS from Autozone or wherever (somewhere with a good return policy). Just start with the cheapest stuff first, and work your way up from there.