Pulling it in I knew it was a vacuum leak. But the car would drive fine but idle real bad and sometime feel like it would die at any moment. At the dealer I don't ever look at the P codes. I had an E46 a couple weeks back with a rough idle and check engine light. The info is then processed by the DME and fuel trims are adjusted accordingly.
All it does it read the amount of air/ oxygen passing by it. I haven't worked on a BMW with O2 sensor faults yet so i could be wrong. I would think, unless you are have faults for the heater circuit (if BMWs) have one or if you have slow movement faults, there isn't a problem with the O2 sensor. Please let me know if you have any suggestions Now I am reading a lot of post that point me to way too many directions, so I am hoping some else had seen exactly my problem. Clean the MAF Sensor ( I saw in the forum this could be the problem).I replaced the Ignitions Coils (my self) with the oem Bosch brand.Took it to dealer for Tune UP thinking spark plugs were bad (misfiring).Engine light came, I took it for a scan and gave me P0171 and P0174, which is system too lean in bank 1 and 2.Since yesterday I starting hearing a buzzing noise that sounds like air flow noise.
Problem has been happening for a few months, sometimes I might go for about 2 weeks without it.Sometimes car engine stops, but start again if I press the start button.This happens when approaching stop light.More gas is injected to raise the rpms, so acceleration goes up and down from the 600 rpm to about 1500 rpm.