Code 171 lean left bank help please

[Makohawaii]

Aloha
I just got this code again po171 lean left bank, car is still running fine. This is the third time getting the same code, first time the dealer replaced the intake manifold, second time he put an injector cleaner into the fuel and then reset the code, any ideas?
2004 ML 350
62000 miles
Manifold was changed at about 48000 (best guess)
Also car is driven by my wife who does not have a heavy foot and never "opens it up".
Thanks in advance

[slimbelly]

I just fixed the same code in another car by replacing MAF sensor. It can be trigged for several other reasons as well. Inspect the intake hose to see if there are any leaks first.

[43sqd]

Code P0171 is not used by M/B and you listed the wrong bank (left). If it was the correct code it would be the right bank.

If you are using a $50 code reader you are getting the wrong information. A better, more expensive scanner will be needed. M/B uses P0170 (right bank) and P0173 (left bank) to indicate Fuel Trim problems. These two codes include both lean and rich problems and the data on the scanner will indicate whether you are running lean or rich.

Freeze frame data must be looked at first to indicate at what speed, coolant temp, etc. this code was set. Without this info it is all guess work.

[Makohawaii]

Thanks for the responses, yes I am using a cheap scanner. Guess I'm off back to the dealer

[Makohawaii]

Help again please,,
Just got car back from the dealer, they checked and said its he mas sensor and wanted to charge 975 o change it, so I took the car and changed it with a reman from pep boys and to my surprise that's not the problem,
I spray carb cleaner along the fuel rails and in the injector area on the drivers side and the engine makes a sucking sound and sputters, I did have the manifold changed about a year ago, it was cracked.
The dealer listed these codes also
Dtc readout codes p2017, p2086, p2085, p2016 adaptations at idle speed and part load both left and right bank, misfire code #4 Clyde coil and resistors

Any options is greatly appreciated

[Makohawaii]

#4 cyl

[43sqd]

There is obviously a vacuum leak at either the intake manifold or the injector/s.

Do you plan on doing this (remove the fuel rail and or the intake) yourself?

[Makohawaii]

No I'm not planning on doing myself, would you guesstimate a cost for repair?

[ruggler]

Originally Posted by Makohawaii

No I'm not planning on doing myself, would you guesstimate a cost for repair?

If you have any mechanical experience you should be able to do this repair yourself and save an ASS load of money in the process. 43sqd is right, its a vacuum leak and could be as easy as an injector o-ring or an intake manifold gasket. Maybe the intake bolts backed off a little since it was repair not that long ago. The dealer is going to rape you judging by trying to charge you $975 for a maf! I'm sure the knowledgeable people on this site will be able to walk you through it if you want to give it a try.

[43sqd]

Originally Posted by Makohawaii

No I'm not planning on doing myself, would you guesstimate a cost for repair?

On the main page of this forum there is a labor hour guide. Your info can be found on page #252.

http://www.benzworld.org/forums/w163...ml#post3761452