LEAN FUEL BANK 1 & 2 and MISFIRE BANK 1

today i did some work on my xi i replaced squealing mech pulley with hydraulic pulley, repaired leaking temp sensor o ring with one from home depot and also replaced throttle body gasket in the process of replacing my throttle body gasket trying to fix these codes i figured i would pull off disa valve. I checked for the signs of a bad disa which is rattling from flapping piece and unplug connector. It wasnt until i pulled it out and inspected it I noticed lots of buildup, worn out flap, and worn out crank which controls open and close of flap. i dont know if this will fix it yet but just wanted to inform my fellow man to inspect disa. next i will order german auto solutions repair kit.

Things replaced/done thus far:

- cleaned maf sensor
- replaced throttle body gasket
- replaced intake boot
- replaced air filter
- replaced ccv & hoses
- replaced fuel sending unit wire harness
- replaced fuel pump
- replaced fuel regulator

Sounds like a MAF

Sent from my SAMSUNG-SGH-I747 using Bimmer App

i cleaned maf sensor i will look further into that once disa is fixed trying to eliminate all possibilities of things it could be before last resort of taking it to dealer i also have to check spark plugs for oil to see if valve cover gasket needs to be replaced and also have to check ignition coils

Check your vacuum lines...start from the egr valve and trace along the side where the oxygen sensor connectors are attached. Then it goes to the back of the engine under the cabin filter housing. You are going to have to remove the cabin filter housing to find the rest of the hose. Then the hose connects to a black and white one way valve and then to a another valve on the driver side back top of the engine block. This is usually the place where there is a disconnect or a crumbling hose has occurred. It is difficult to reach, but doable.
If you do a search in the forums for "failed smog inspection," there are detailed instructions on how to do this, and then there is a great way to rule out things that are failing..

This has not happened on my Bimmer but I did get these codes on my GMC truck. Changed the related oxy sensor and all was well.

if it was oxy sensor would i be gettin lean on bank 1 & 2.... arent these codes a sign of working oxy sensors

Originally Posted by louie101086

if it was oxy sensor would i be gettin lean on bank 1 & 2.... arent these codes a sign of working oxy sensors

It's a sign that your O2 sensors are sending a signal, it doesn't mean that it's the right signal.

How many miles do you have and have the sensors ever been replaced?

i have a little over 170k miles and i do not know if o2 sensors were ever changed.... i think i will fix my disa valve first then reset service engine light and if light comes back on i will change o2 sensors if i change sensors should i just change the 2 by engine or change all 4

Just change the pre-cat sensors, the post cat ones rarely give out.