I have a 2002 325ti with a rear muffler delete and the exhaust occasionally crackles and pops on the overrun in the lower rev range, if I lightly tap the throttle around 1600-2000 rpm on a warm engine it reliably makes some funny noises. I assumed it might've been a weird remap by the previous owner (which wouldn't surprise me considering the car's history), but I reflashed the DME to the newest stock software with Bali's instructions and it still does it. It's good fun during city cruising, but to me it seems odd for a (relatively) modern fuel injected engine to waste fuel like that, is this normal for a muffler-less M54 or am I right to be worried?
Also god damn is it difficult trying to find info on this subject, all I get for searching is endless threads of people wanting to flash intentional crackle maps instead.
Also god damn is it difficult trying to find info on this subject, all I get for searching is endless threads of people wanting to flash intentional crackle maps instead.
as it seems there is excess raw fuel in the exhaust. Use OBD2 and get a log file for a warm idle and cruising for about 3 minutes log each. This will tell how is the fuel mixture for your engine and why it backfired.
