Wow, you guys have been busy discussing this in my absence

Tony is right about my typo, I meant "only".

So, the handshaking lines shouldn't matter at all since I have handshaking turned off in my program, my program also sets the baud rate first thing so that shouldn't be a problem either.
Also, I have determined that the problem isn't with the sled since the program is no longer working from the port on the back of the empeg as well.
I'm guessing that something is going on with the wideband when it is installed in the car that wasn't happening when it was on my kitchen counter (where I wrote the software).
The thing that is strange to me is that my laptop can talk to it fine. Is the empeg known for having a finicky serial port?
I didn't get around to hooking an ethernet line up to the empeg today to see if I could do some debugging. I'll hopefully do that in the morning.
It's a strange thing. I had it working great in my kitchen and then installed the wideband in the car and went to test it. I then realized that the sled serial port was different and assumed that must be the problem. It seems that my assumption was wrong and there is something else strange going on here...
Thanks for all of the analysis though!
I'll keep you posted if I learn anything.

-Jeremy