All Onkyo and Integra receivers use the same IR code-set. If Harmony do not have the Audyssey codes set up for your particular model try using a different one. Which Onkyo do you have?
Here are the codes in Pronto CCF format for a lot of different receivers:
http://www.awe-europe.com/ir_232.html
If you download the spreadsheet for your model you can see which codes it is capable of responding to.

I've got an TX-NR809, the codes I found were for the 607, I think.

Yeah, after looking at that sheet, I think I've got the right ones. I'll see if Harmony responds; I don't really want to deal with changing the receiver type if I don't have to.

Logitech support has informed me that since my remote is more than 90 days old, they won't help me. I've asked to speak to a manager, since that's f*&!ing ridiculous.

Did they say why 90 days was the cutoff?
Did you get to talk to upper management?

Haven't yet. I just got the email back today, and emailed them back. They said 90 days was the cutoff. Hello, Logitech, it's a cloud product. You can't give up cloud product support.

If you had 2 harmony remotes you could put the codes on one and teach it to the other.Does the codes for the 607 work on your 809, you could add the 607 as a phantom device and map a button to its codes.

Pity my other Harmony's USB port is dead.. but I like the idea! I may just try and switch the remote over to another Onkyo receiver to see if that one has it. After I yell at the support manager for awhile.

I wish I had your problem , then i would have a good excuse to get the new harmony touch.

I wouldn't be getting any new Harmony products until any potential sale has gone through and the future support is shored up. I quite like the look/idea of the Roomie