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· Registered
98 ML320
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27 Posts
Discussion Starter · #1 ·
According to AutoZone:

P0170 and P0173...
The PCM has determined that during testing, the fuel compensation valve for bank 1 [and two] exceeded the specified range.

P0400...
The PCM has determined that malfunction exists in the exhaust gas recirculation flow.

It was at the dealer [Beck Imports - Charlotte, NC] a few weeks ago to diagnose a fuel/exhaust odor, loose steering, and excessive engine vibration. They called me an hour or two later to tell me that the only thing wrong with my car was bad engine mounts. I can live with the vibration for $460. I knew there was something wrong with it still, so I went to my school and borrowed their lift. Immediately I noticed a small exhaust leak (maybe?? definitely notice carbon buildup) just ahead of the muffler and busted tie-rod ends. I checked and it had the correct part number for the (still) wobbly harmonic balancer. I felt the cats and didn't notice any cracks in them. ~~Long story short~~ Called dealer's service manager...brought car back...they agreed with me about busted tie-rod ends, and said I didn't have an exhaust leak, but it had an oil leak that needed to be fixed. I specifically asked the guy on the phone if the oil leak would be the cause of the exhaust smell, and he said yes. I let them fix that, and it seemed to make the problem hit or miss enough to where I would have a difficult time getting them to notice it, so I've let it pass until now.

This week the exhaust smell came back more frequently and today the engine light came on with those codes? I can't "see" anything wrong, but I can definitely smell exhaust coming from around the engine area (mainly right side). What part swaps do those things entail? Any help is appreciated [:)]
 

· Super Old Fart Moderator
2002 ML320, 2010 F150 Crew Cab
Joined
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12,148 Posts
Is search feature working?

PO170 and 173 is the Mass Air Flow sensor. I do not know if PO400 is related as well, but I think that it is the EGR valve. Replace MAF sensor FIRST! The EGR is a PITA.
 

· Registered
98 ML320
Joined
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27 Posts
Discussion Starter · #3 ·
http://www.nology.com/OBD2FaultCodes.htm

I'm guessing OBD2 is universal...they pretty much coincide with AutoZone's discovery...unless M-B has their own codes...

BTW...1998 ML320 141,900 miles...7000 left on FSS...
 

· Registered
ML55
Joined
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62 Posts
P0173 - P0170 is MAF as mentioned here earlier ... but (also as you do the search) try to clean it first. It just happened to me 2 days a go, same codes P0170, P0173 + P0442 - EVAP, but after cleaning MAF the Check Engine Light went off ... it's been like that for 2 days [;)] ...
 

· Super Old Fart Moderator
2002 ML320, 2010 F150 Crew Cab
Joined
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12,148 Posts
busoptr said:
p0400 means random/multiple cylinder misfires. Replace your spark plug cables. All of them.
According to the OBDII site, the P0400 is the EGR flow malfunction. No mention of multiple cylinder misfires. When my EGR valve went bad, it threw this code.

http://www.obdii.com/codes.html
 

· Registered
2002 ML500 Silver
Joined
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76 Posts
Yes, correct post above.

Set aside two hours and clean the EGR tube. Mine was 99% blocked.
It is a pain to get out and back in but the satisfaction was well worth it.

It was difficult to work the tube out and back in but you will get it.

Tools I used:
Adjustable wrench to get the large nut off
8mm wrench to remove the intake support and the two bolts holding the EGR flex tube.

Degreaser and a screwdriver to remove the black buildup from the tube.


Car runs so much better on decel now and no codes!
 

· Registered
'01-E320 & 02-ST2
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31,798 Posts
Hey, BU2MORICI, welcome to the forum. Please take a minute to click the User CP link and complete your BW profile re: vehicle and location as that is almost always useful information, especially when you're seeking advice.

Resetting the service indicator is covered in your manual, follow the steps in there closely and it will reset.

Which bank 2 sensor are you looking for? On a V MB engine bank2 is on the driver's side (at least outside of the UK and down under), or the right side of the engine when viewed from the front of the truck (everywhere).

Last thought, just a friendly reminder, hijacking an old post with different questions or issues just clutters things up. If you search and can't find one that fits, then just start a new thread, makes it easier to keep track of things. :thumbsup:

Take care and enjoy the ride,
Greg
 

· Registered
2002 ML55 AMG, 2005 Chrysler Crossfire Coupe Limited, 1999 C280
Joined
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4,715 Posts
Hey, BU2MORICI, welcome to the forum. Please take a minute to click the User CP link and complete your BW profile re: vehicle and location as that is almost always useful information, especially when you're seeking advice......Last thought, just a friendly reminder, hijacking an old post with different questions or issues just clutters things up. If you search and can't find one that fits, then just start a new thread, makes it easier to keep track of things. :thumbsup:

Take care and enjoy the ride,
Greg
Greg, you're such a gentleman!:D
 
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