P0171: System too Lean (Bank 1)

2009 CL63..Anyone have any ideas for what may cause these error codes?


Historic Fault Log
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ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
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P0745: Pressure Control Solenoid "A"
P2091: B Camshaft Position Actuator Control Circuit High bank1 c)

 

Could be a leak in the intake manifold gasket.

 

I would concur with a vacuum leak. Usually downstream of a flow sensor. Could be something like a loose connector or rubber gasket.

 

Well The air filter had three screws missingI replaced them and cleared the codes. Guess what? They never came back. Thanks for your input.

 

Glad it worked. I have had a situation where the last two times I have traveled in my CL (over 150 mi.), toward the end of the trip every light in the dash comes on. I mean it takes two iterations of dash flashes to get all the warning lights. Nothing feels different.
I know I will need some type of deep analysis of codes that my standard code reader will not reach (shows no codes after this event). Just bring it up because I appreciate how frustrating the warning light thing can be.

 

I had the same error code and a CEL, along with the characteristic "whistle" when shutting the engine off. Crankcase ventilation valve. Required removal of the intake manifold to gain access to the crankcase fitting. I replaced all my injectors while the manifold was out of the car. Not a difficult job if you have a decent set of tools, including Torx drivers.