Hey everyone I'm really having a huge headache with my 2008 ML63. I went to the dealer for CEL code P0171 and the SA told me that it may be a crack on the manifold so they went ahead and changed the intake manifold and seal. A few days later the light comes back on. The new manifold did give the car better response and power but the CEL is still on. I also changed the purge valve cause I saw somewhere on here that it may be that but still nothing. I have warranty which covered most of the expenses but I just wanna get any feedback from anyone who has a better knowledge of this issue before spending another couple of hundred for the deductible. Any advice would help. What I'm planning to do is get a Weistec ECU tune and let them flash the ECU to compensate for the "leak" is this smart? I checked the whole engine for leaks and nothing. Please any help 63 guys?