If it's AAN then check it with VAG-COM, maybe that "pop sound" was backfire that destroyed MAF.
I don't think it would start with diesel, one guy some time ago tried that with he's vw G60 engine - there was thread in that vw forum - for two pages he tried to figure out why he's G60 suddenly died, then he realized he put diesel in thank, after that there was loughing for 10 pages
