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2001 ML55 AMG, 2005 E55 AMG, 2000 ML55 AMG, 2000 C230 Kompressor
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Discussion Starter #1
Posted this also on MBWorld so figured I'd put it here too..................I've got a 2000 ML55 w/ 173k that I recently picked up and have been trying to get it back up to speed. The previous owner for some reason never addressed the water leak on the driver and passenger footwells. As a result, the O2 connectors on each side are shot and I get the following codes: P0141, P0161, P0136, P0156 even with new O2 sensors. Upon further inspection, it appears that the connectors are corroded.

Not sure it is worth the effort to replace these connectors - does anyone know of a way to code these out? I was unable to figure it out in STAR but I know the guys on the W211 AMG forums have done this. Not sure it applies to the W163 chassis though as well.

Look forward to any input!
 

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w163 02 ML500 W210 97 E50Amg w202 99 C230K w124 - need more space, time to build again
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Posted this also on MBWorld so figured I'd put it here too..................I've got a 2000 ML55 w/ 173k that I recently picked up and have been trying to get it back up to speed. The previous owner for some reason never addressed the water leak on the driver and passenger footwells. As a result, the O2 connectors on each side are shot and I get the following codes: P0141, P0161, P0136, P0156 even with new O2 sensors. Upon further inspection, it appears that the connectors are corroded.

Not sure it is worth the effort to replace these connectors - does anyone know of a way to code these out? I was unable to figure it out in STAR but I know the guys on the W211 AMG forums have done this. Not sure it applies to the W163 chassis though as well.

Look forward to any input!
Have you tried first removing ALL the moisture and water that may still be trapped under these heavy padded carpets, including using CRC electronic cleaner on all the connectors?

Also, with the new o2 sensors installed, did you try erasing the codes after installation?
 

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2001 ML55 AMG, 2005 E55 AMG, 2000 ML55 AMG, 2000 C230 Kompressor
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Discussion Starter #3
Khomer2 - thanks for the response. Yes I should've mentioned this that I've actually had the carpet completely out of the car for a thorough cleaning and sat in a heated room for a week to ensure that heavy padding at the bottom was fully dry. Annoyingly enough, I had said to myself when looking at the top side of these O2 connectors, 'wow whatever these are don't look too great', I should've looked more into it before putting the carpet back in 😒. Anyhow, with the new O2 sensors installed I did erase the codes after installation and they appear back within 30 or so minutes. I cleared it a few times and once it came back again for the 3rd or so time I went back underneath removed the sensors again and noticed that 2 of the pins were corroded enough that when I unplugged the old sensors 2 of the pins totally disintegrated.

So I figured this is going to require new connectors or I can avoid all that hassle of getting up underneath there and coding those rear O2s out.

Have you tried first removing ALL the moisture and water that may still be trapped under these heavy padded carpets, including using CRC electronic cleaner on all the connectors?

Also, with the new o2 sensors installed, did you try erasing the codes after installation?
 

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w163 02 ML500 W210 97 E50Amg w202 99 C230K w124 - need more space, time to build again
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Khomer2 - thanks for the response. Yes I should've mentioned this that I've actually had the carpet completely out of the car for a thorough cleaning and sat in a heated room for a week to ensure that heavy padding at the bottom was fully dry. Annoyingly enough, I had said to myself when looking at the top side of these O2 connectors, 'wow whatever these are don't look too great', I should've looked more into it before putting the carpet back in 😒. Anyhow, with the new O2 sensors installed I did erase the codes after installation and they appear back within 30 or so minutes. I cleared it a few times and once it came back again for the 3rd or so time I went back underneath removed the sensors again and noticed that 2 of the pins were corroded enough that when I unplugged the old sensors 2 of the pins totally disintegrated.

So I figured this is going to require new connectors or I can avoid all that hassle of getting up underneath there and coding those rear O2s out.
If it were my w163, I would want to make sure the O2 sensors are working correctly. These are the O2 sensors for the front as there there are no sensors for the rear and the system doesnt have any link to what happens back there.
That being said, on another note, and depending on your state laws, you could remove the cats and straight pipe that portion to get better flow.
 

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2001 ML55 AMG, 2005 E55 AMG, 2000 ML55 AMG, 2000 C230 Kompressor
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Discussion Starter #5
If it were my w163, I would want to make sure the O2 sensors are working correctly. These are the O2 sensors for the front as there there are no sensors for the rear and the system doesnt have any link to what happens back there.
That being said, on another note, and depending on your state laws, you could remove the cats and straight pipe that portion to get better flow.
This is exactly what I was looking to do, delete the secondaries and install new primaries but I'd love to get rid of this check engine light.................has anyone coded these O2 sensors out? I'd love to hear if it even possible!
 

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w163 02 ML500 W210 97 E50Amg w202 99 C230K w124 - need more space, time to build again
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We had a very recent discussion on a similar o2 sensor topic (w163) asking if it were possible to adjust the trims (look thru the recent w163 threads)
Im not familiar with this; that discussion looks to be "not doable".

If you already replaced the sensors, then it's very possible your connections are not picking any readings of the new sensors?
Maybe re-clean the connections and re-connect?
 

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2000 ML55 sold😢 2013 ML500,😁 2015 C250 estate wagon, 1927 Dodge 4 sedan, 1929 Dodge
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The only way I have heard about doing it is to put an adapter on them to set them back a little. This won’t cure your problem as you need to replace the wiring and connector.

 

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CURRENT: 2011 SL550, 2011 C300 FORMER: ML350, CLK550 Cabriolet, C240, ML320, 300TD
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There are ECU tunes that can code them out. They can code out the front O2 sensor,s too, in case you want to do headers.
 

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Discussion Starter #10
Thank you everyone for the responses here!
 

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Discussion Starter #11
There are ECU tunes that can code them out. They can code out the front O2 sensor,s too, in case you want to do headers.
rudeney - do you happen to know which ECU tuner can do this? I'll do some digging too.
 

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1999 E320, 2003 E320 Wagon, 2005 C230K SS, 2010 Accord LX w Eibach & Koni FSD's
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Are the connectors necessary? Can it be hacked by just splicing the wires together?
 

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I'm not sure which ones do it, but I know on cars with headers, they code out both front and rear O2 sensors. A guy on the W209 forum did this on his years ago. I'd Pm some of the more reputable ECU tuners and see what they have to say.
 

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Discussion Starter #14
thank you rudeney and 260e cruiser.....I will definitely have to assess those options both...............but quick update........I was scanning through eBay trying to find these connectors (after many dealers basically telling me to kick rocks with your old ML) and stumbled upon these:

2608831


Obviously don't need the O2 sensors that these come with but need the wires and respective pins in the connectors as that is where my issue lies. I've ordered them and they should be here shortly...... hoping this works!
 

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