I am generally an 80's w123 diesel owner, but could not pass up a great deal on a 1995 e320 wagon, even though we were told it "has issues". Ticking them off the list one by one and I'm to the o2 sensor. I read that the front o2 sensor is wired under the passenger's floor mat, and that a good first step is to simply look and make sure the connection is sound. I removed the floor mat and...well...things aren't pretty down there.

Below are some pics. Is the cruddy horrid mess in the red circle the connection I'm looking for? Or is it hidden under the case with the other wires that I've put a green rectangle around *crosses fingers for that option*?

And then...if it is that crud covered monstrosity... That would probably be my very first bet for getting o2 codes. Can that be cleaned? And if so, with what?

Thanks for any answers you can give!

Attached Thumbnails

   

Green wire....

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1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

Thanks!

I'm just going to have to try and clean it. Even if I order a new o2 sensor, it won't come with the connection to the engine. As bad as it looks when it's connected, it's just as bad inside.

If your wiring pins are corroded you can buy those pin connectors (both male and female) with some pigtail wires from MB.

You would need some very fine tools to take this apart and install the new pins, once you have fresh metal in there solder the wiring harness to it.

I repaired my antenna wiring plug like that - but I had a snipped off connector lying in my toolbox, I undid the connector and extracted a couple of pins with wires. Look up some articles for it. If this connector is the round pin type you are in luck, they are very easy to repair. My antenna connector had the miniature flat pins that modern MB have and are much more involved.

It looks like water has done some bad there, find the source of the leak or you might be looking at rust problems soon.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

So if I muck it up cleaning it, it's not a lost cause? Good to know, thanks! I do computer work, so I have the fine tools, and I was thinking that the connector looks an awful lot like some 4 pin computer wiring hardware...

I don't know if it's leaking so much as got really melty. What you're seeing as rust seems to be more...char. Slight to moderate singing. lol The thick black wire the previous owner installed for some accessory that's no longer with the car is melted through the padding. What looks like water drops are melted plastic. That sucker got HOT. I took the cover off that wiring case, and fortunately nothing in there melted.