P1336 code

[OKGMC4]

Getting this now on my 01' 5.3l. Not sure why it waited 150 miles to pop up but it won't even clear with an AutoXray scanner. Tried googling this but basically came up with these options...

1. Pay GM at least $100 to do a CASE relearn with a Tech II
2. Spend $600 to get HPtuners or EFILive and do it myself, though it might or might not actually work
3. Buy a $3000 OTC Genesis scanner to do it.

Does this sound right? Any other options? I was really hoping there was a handheld tuner out there somewhere that I could use but none of them seem to have CASE learn options. Seems like a ton of money on a 5 minute fix. If anyone has a better idea please let me know. Thanks...Mike