Heckler, I feel your pain. Now lets see here. Left and right bank too lean... Star with the MAF. Take the assembly out and look inside. If there is a lot of junk, blow compressed air and clean it a bit. See if that works. Also (I had the p0171 code and this cleared it) There is a vac hose that connects to a solenoid. My hose was busted and threw the code. The hose attaches to a system under the plumbing of the air box (Between the air filter housing and throttle body assembly) and then runs on top of the intake and connects to that solenoid and then tee's off to the secondary air canister that sits to the left rear of the intake.

Also have you thought about the system running too rich? It could be running rich and the computer is fooled by throwing a code that it is running lean. Oxygen in the system could be fooling the computer to add more fuel to the system, trowing the balance off. How is the gas mileage? Sorry for just throwing things out there. But it is hard to tell. Hope the suggestions help.

Oh and after my valley pan fiasco, if the X decides it doesn't wanna start after a test run, I'll hook 'er up to my Duramax and whip er around the block a few times. You know, to know it whos boss.

__________________

2011 E70 50i M Sport