But in my case I had the ping even with the old nozzles. I also remember that when I was running B20 the ping was nearly non-existent so you might be right that it's a timing issue (bio burns sooner and slower). But I'm not sure if I want to mess with the timing. I eyeballed it a couple years ago and it seemed spot on and normally it's not supposed to be changed. Yesterday I noticed that my EGR valve doesn't move anymore when I rev the engine (it's in the normal, minimal EGR position). I wonder if that has anything to do with the ping.

__________________
2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL