P2187 & P0171 Codes
08-26-2015, 12:07 AM
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P2187 & P0171 Codes
Check engine light recently came on so I pulled the following codes - P2187 & P0171 - Both are saying System Too Lean (Bank 1) Car is a 2008 E63 AMG. Can anyone give me some advice on where to start? MAF sensor? O2 sensor? Vacuum leak? Pretty much new to this car so before I start it would be nice to get some input. Car seemed to run fine although it had a tiny bit of a rough idle. I parked it since the light came on to do some research to make sure I didn't do any harm to the car. Any input would be helpful. Thanks in advance.
09-08-2015, 11:13 PM
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Doesn't look like it was the MAF sensors. Going to replace the intake manifold gasket & purge valve and see what happens then. Looks like MB had a service bulletin on the intake manifold gaskets & bolts.
09-09-2015, 07:44 PM
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2007 E63
I think you're on the right track in replacing the intake gasket. Have you tried the carb cleaner spray trick? I believe those are the same codes I had. When I sprayed carb cleaner near the back of the intake there was an obvious leak evidenced by a stark change in idle. I also had a less obvious leak in the front. Do you have the ability to view live information on the fuel trim? If so, look to see if the values drop with increased RPMs. Often with intake gasket leaks the lean condition improves with increased RPMs because more air is needed to achieve ideal AFRs. An intake leak has greater affect on the AFR at idle when less air is required.
If you do replace the intake gasket, I'd very highly recommend replacing the PCV valve. Not only can it be a source of air inflow not measured by the MAF sensors (causing a lean condition), but on the M156 it is a difficult task without removing the intake. With the intake off to change the gasket, it's very simple to replace. You might as well change out this wear and tear part while you have 99% of the laborious work involved to do already.
If you do replace the intake gasket, I'd very highly recommend replacing the PCV valve. Not only can it be a source of air inflow not measured by the MAF sensors (causing a lean condition), but on the M156 it is a difficult task without removing the intake. With the intake off to change the gasket, it's very simple to replace. You might as well change out this wear and tear part while you have 99% of the laborious work involved to do already.
Last edited by Dryfly; 09-11-2015 at 02:58 PM.
09-11-2015, 01:22 PM
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Thanks for the reply Dryly. I haven't had a chance to do much in the last week but have all the parts now and will be doing this over the weekend. I'll let you know how it goes.
09-18-2015, 02:43 PM
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Looks like the intake manifold gaskets were the issue. Replaced these and the PCV valve and all seems to be good now. I only have a couple hundred miles on it but before it would trip a code after about 100 miles.
09-18-2015, 05:20 PM
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2007 E63
Glad to hear you appear to have the problem solved. It really isn't that difficult of a repair.
06-14-2023, 08:31 PM
#7
Same issue 07 e63
Hello everyone. Guess what? Check engine light decided to show up few days ago. I ran the codes and it shows exactly these two codes. Can you tell me how hard it was to replace those parts yourself and how long did it take you? And how much were those parts? I am brand new to Mercedes Benz and a little help will be much appreciated.
cheers
cheers
