CHECK ENGINE LIGHT IS ON

[jdstrickland]

Originally Posted by Bayerische Motoren Werke

2003 X5 3.01 AWD
Check engine light is on.
I have replaced my DISA valve and also replaced the MAF.
Spark plugs are new, air filter is new, Fuel filter is new.
I am getting code P0175 Bank 1 System too lean
P0172 Bank 1 System too lean.
Any cluese what is causing these codes?

POINT OF ORDER
Lean codes are P0171 & P0174. The codes you gave are for Rich, not Lean.

P0170 & P0173 are Malfunction
P0171 & P0174 are Lean
P0172 & P0175 are Rich

Since there are specific codes for lean and rich, I assume that "malfunction," means that the fuel trim/control swings between rich and lean -- it is unstable enough to be wrong, but not consistently wrong to be one or the other.