just fitted baileys dv slight pop from exsaust now and again why

 

overfueling due to the air going to atmosphere rather than back into the engine.the extra fuel goes down the hot exhaust and pops and bangs.

 

could it do any damage

 

na, they all pop and bang when decatted, and even more when the recirc dump valve is replaced with a vent to atmosphere one. mine does it and sounds great

 

Cant the extra fuel in the cylinder lead to bore wash and oil contamination?

 

you get that when the mixture is very rich, a lot of the time. if your going flat out the mixture is right and everything is good, then you let off so the dump valve throws the air out but the ecu thinks that the air in still in the system and puts the fuel in as normal. its only rich for a few rpms and that goes down the exhaust and pops if hot.

 

also noticed revs jump up a couple of hundred when changing gear