TPS only allows one set of tires and wheels at a time.
 

This is an FYI to everyone...

I bought a second set of stock wheels with TPS sensors and got some winter tires mounted on them and then I brought the TPS ID's to the dealer to have the second set programmed in. The ECU only allows for one set TPS sensors to be programmed in at a time. :(

IMPORTANT: make sure you have you tech's write down the TPS ID's already in the computer before they switch you over to the winter set, other wise you might need to have you tires dismounted to get the ID numbers back when mount your summer tires back up.

correct and good info

How much was the charge to re-program the ECU?

Not sure as they didn't complete the service (the service writer didn't charge me for the attempt).

This topic already had some air time here:

http://www.ft86club.com/forums/showthread.php?t=5970

FWIW, when I ordered wheels at America's Tire, they said they can clone the IDs from my TPMS sensors to a set of new TPMS sensors, and then I can swap between sets of wheels with no problems.

The line on the receipt says
SCH 33520 TQ12 T10 315/433 EZ TPMS SENS SNAP IN 33520
— I presume these are Schrader EZ-sensor.

They used Bartec Tech400Pro to do the ID cloning.

Sadly, I couldn't confirm if the sensors worked afterwards, since the wheels didn't fit, but that's a different story.

2012...

Much cheaper way of getting a second set is picking up toyota/lexus sensors off ebay for $50 and then getting an ATEQ quickset ($150) to change it yourself between winter and summer tires. Any chance to avoid going to the dealer I take...

Yep, this is true of most Subarus. You should get an ATEQ TPMS QuickSet and save both IDs into it and then you can swap them easily at home yourself without having the dealer do the reprogramming. It's like $90 on Amazon and you'll never need to have someone else program TPMS on any car for you again.

You're right, it's not the most fresh.

However, this thread is still pointed to by this sticky thread, which probably brings some attention here still.
The other one is 10 pages long without a clear explanation of what to do for folks who want to program TPMS in their new wheels -- it's hard to get the right information from there, which is clear from the number of "I'm a newbie, so what is it that I should do with these sensors?" messages there.

I think what we need here is a new thread where someone who knows a clear answer puts the summary in the first post, and update that sticky thread to point there.

So how would it work with the tire/wheel packages that some websites offer? I always wondered.

Looking to get into some new wheels and I don’t know if I should get the tire/wheel package or order separately. I could easily take the sensors from the OEM wheels and switch them over for a new setup, but that’s obviously very inconvenient. Plus, I’d like the free mounting, balancing, and shipping that comes with a wheel/tire package.