Hi guys,

Overtime I have noticed my fuel economy has gotten worse. From 7L/100km to 8.8L/100km. I also noticed the tail pipe is very sooty. I cleaned it and gave it a nice polish 2 weeks ago and it is already black! Acceleration is also slightly slow. I wonder if you guys can shed any wisdom on what’s going on? I don’t have any check engine lights on and after using a Bluetooth obd2 reader, I don’t have any codes. Can running rich not trigger any codes? What can I do?

thanks

oil is changed every 8000 KM
current odometer 117,000 KM
fuel filter, spark plugs, changed 3 years ago

 

What are your fuel trim numbers?

The easiest way to see your STFT and LTFT is to look at the live data under OBDII instead of going in through the BMW menu that's available on some diagnostic tools.

 

Does your code reader and app support BMW codes? Consider re-checking the spark plugs.