2001 E53 System too lean bank 1 and 2 error code help needed!
 

Hey guys, I have an 01 X5 with ~84,000 miles. I got this error that the system is too lean in bank 1 and bank 2. I took it to an indy shop and they ran a smoke test to tell me my oil seperator hoses needed to be replaced. I fixed those and then the light came back on and then I took it to another shop that told me I needed new O2 sensors, so I replaced those. Now the light is on again for the third time with the same issue. I am sick of throwing money at the problems and need to try and pinpoint what exactly is wrong!

The car idles good, no sounds of vacuum leaks (that I can tell), it does lag a touch in the power dept. and seems to shift funny. It also burns coolant like it is going out of style...Oh, and when its really cold outside the SES light goes off and then when it warms back up the light comes back on...Can anybody help?

Thanks!

Check the DISA.

From a friend: It opens and closes a flap in the intake manifold to give you more torque in the low RPM range and more power in the upper RPM.
At <3750 RPM a solenoid is energized which controls the vacuum to close the flap, it allow air to enter thru one tube but at a higher velocity for more torque output.
Above 4100 RPM the solenoid closes, the flap opens and air now enters thru 2 tubes increasing the volume needed for high RPM and power output.

I had similar symptoms as you when mine went.

http://www.bimmermail.com/part.jpg

Rubber boot on the throttle body was my cause for this fault. Cheap repair but a real pain to get at.

check your hoses... especially the ones coming off the secondary air system vacuum pump valve.

Ok, I am going to try and check the DISA in the morning...How would I know if its the boot on the throttle body without getting at it?

As far as I can tell, this DISA valve in on the 3.0 and not the 4.4i...is this correct?

OK, I looked up a detailed diagram of my vacuum lines and did a thorough check. It appears as though a blue hose that runs to my electrical valve is broken. I am going to try and replace it and see if this works...fingers crossed!

That's possible. I didn't know which engine you had.

if your burning antifreeze u might want to worry about that and find out where it's going.

I am driving an 01 4.4i with 58k.

Had the same kinda issue. Hard to diagnose. Dealer mis-diag x2. Ended up with a free injector, injector cleaning and a deal on a MAF.

MAF does not affect this issue. Weasel recommended checking for vacum leaks by spraying brake cleaner onto the suspect areas while a volt meter is attached to the first o2 sensor. If there is a vac leak, the sensor will spike when the brake cleaner is taken in and burned.

ANYWHO.. the issue was a blocked cat. Motor idled and advanced fine. When under load and a higher RPM, it was boggy and the SES flickered, then came on. Ended up being a blocked catalytic converter. Replaced and all is fine. Runs quite well. They have a meter to test flow rate. It should read 0 for no block. Mine went up to a 3 on one bank, FWIW

Price is high. 1900.00 for dealer to do the work.

Good luck.