Question

2003 BMW 745i 4.4L too lean at idle bank 1 & 2, what is the problem?

Answer 1

HI there,

Normally when you have lean codes for both banks on the engine it's a result of a bad mass air flow sensor or low fuel pressure. The fuel pressure should be tested to determine if it's the problem as well as the mass air flow. If you have an intake leak AFTER the mass air flow sensor you can get these codes together as well.