Alrighty. I finally dived into the flashing process after acquiring hardware and software needed for normal/bootmode flashing. I knew beforehand by studying boost logs that the car has a tune of some sort and I didn't know if it perhaps was a Revo or APR one (**horror stories about "Programming not finished" stories floating around in my mind**), but I successfully read the 06A906032HJ (AUM) flash off my ECU. Battery and laptop both plugged in to chargers when doing reads/writes to the ECU.

After doing some research I found that the 1.8T AUQ virtually has the same engine components as the AUM, so I went ahead and modified a stock 06A906032HN (AUQ), deleting the SAI and modifying KRKTE and KVB to suit the 4 bar FPR I've installed to allow running E85 (flex setup with sensor) without maxing out the injectors. The file flashed perfectly, but once I tried to start the engine it didn't fire at all. A quick DTC check in VCDS gave me "P1570 Immobilizer blocked engine start", making my heart skip a beat or two. "Did I just brick it?". It appears I didn't, flashing the original (except for SAI delete and KRKTE & KVB adjustments) file back fixed the problem.

I'm pulling my hair off trying to understand why the immobilizer would go bananas after flashing the new file. I've never had problems with the immo before, so the problem is definitely with the flash.

Thanks! What I have gathered so far is that the engine boosts at around 1 bar and has the timing increased by 3-7° at higher loads, but I have no idea what they've done to the immo functionality. The immo problem is only present if I flash the HN file, and I've managed to do every tune I need on my original file, so this isn't really a problem. I actually just wanted to test the AUQ file as a comparison against an AUM Stage 1 (I guess?) tune.