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Just when I taught everything was finally fixed on my car the check engine light came on. I took it to the Autozone and the scanner said PO 171, left engine bank lean. Anyone have any minor things I could try so I dont waste time going to the dealer if it is something simple. Thanks.
 

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This excessive lean condition can mean a few of things, mostly something is causing the system to go lean beyond what the ECU wants to compensate for. Your motor is probably one of the most problematic motors in modern times, that's why MB dumped it after 2005, shortest run I've seen for an MB motor. First I need to know if your motor is running rough or unusual.

If it is running rough, it's likely the vacuum line under the intake, very common, search for it, part cost $11, most dealers charge $500 to replace it. It will be clearly obvious that this line is bad, it will crumble in your fingers.

If it is not running rough, could be a dirty MAF, remove the MAF, clean with CRC MAF sensor cleaner and put back in, erase code, see if it comes back. If you suspect the MAF, unplug it and drive the car, if it runs better with MAF disconnected, it's definately the MAF.

Also, there's a possibly the cam sensors are leaking oil. Check the connector to each cam sensor, if there is oil, that's a problem. Oil seeps into the engine harness and takes out sensors, typically the O2 sensors. Dealers seem to charge $2k for that one unless you catch it before it happens, then it's fairly cheap to replace cam sensors.

Seach the forum for more info, don't come back and ask where stuff is, it's in the forum.

Good luck.
 
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