Oxygen Sensor Clarifications - (W203 C230 Kompressor)
#26
Super Moderator
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I strongly recommend using the genuine Bosch heated O2 sensors. Universal crap in my experience always gives trouble on these cars. You don't have to buy them from a dealer. Buy them from RMeuropean etc.
#27
Thanks!
Well, I think you're right on that. I will go with genuine on this car. I'm going to sell this thing after I fix it. It needs a battery and an oxygen sensor as well as a revamp of the front suspension. All in all, about $600+ bucks if I do it on my own. This car was my wife's but she's no longer here and I've been using it but I'd rather have a toyota truck or something a little less expensive when it comes to repairs! Thanks for the answer. How about the other question? Any advice on that?
Thanks!
Thanks!
#28
Super Moderator
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Hello. Can anyone tell me what size wrench or socket to use when removing oxygen sensors on C240's? I read it's 3/8" but then I read it was 22mm. I'm guessing it's the metric but I don't want to buy the wrong size. Anyone? Also, can a oxygen sensor socket fit in there? I tried to use an open wrench today and it barely fit. It got too dark so I'll start again tomorrow and I'd like to get the proper tools. Also, I'm getting a code reading of P0173 and P0175. That's bank 2. Bank 2 is the 'passenger' side, correct? Also, would that be the upstream or downstream sensor? Thanks for anyone who can give me the answers!
P0175 = System too Rich (Bank 2)
Bank 1 = 1, 2, 3 cylinder (fuel door side/passenger side US)
Bank 2 = 4, 5, 6 cylinder (drivers side US)
OBDII/CAN regime dictates that Bank 1 is always the bank that contains Cylinder 1
Your fuel trim is monitored by the upstream sensor. The downstream monitors the effectiveness of the Cat.
It's 22mm
![](https://mbworld.org/forums/attachments/c-class-w203/163839d1250679441-o2-sensor-o2-sensor-22mm-socket.jpg)
#29
P0173 = Fuel Trim Malfunction (Bank 2)
P0175 = System too Rich (Bank 2)
Bank 1 = 1, 2, 3 cylinder (fuel door side/passenger side US)
Bank 2 = 4, 5, 6 cylinder (drivers side US)
OBDII/CAN regime dictates that Bank 1 is always the bank that contains Cylinder 1
Your fuel trim is monitored by the upstream sensor. The downstream monitors the effectiveness of the Cat.
It's 22mm
![](https://mbworld.org/forums/attachments/c-class-w203/163839d1250679441-o2-sensor-o2-sensor-22mm-socket.jpg)
P0175 = System too Rich (Bank 2)
Bank 1 = 1, 2, 3 cylinder (fuel door side/passenger side US)
Bank 2 = 4, 5, 6 cylinder (drivers side US)
OBDII/CAN regime dictates that Bank 1 is always the bank that contains Cylinder 1
Your fuel trim is monitored by the upstream sensor. The downstream monitors the effectiveness of the Cat.
It's 22mm
![](https://mbworld.org/forums/attachments/c-class-w203/163839d1250679441-o2-sensor-o2-sensor-22mm-socket.jpg)
#30
I have this socket...
P0173 = Fuel Trim Malfunction (Bank 2)
P0175 = System too Rich (Bank 2)
Bank 1 = 1, 2, 3 cylinder (fuel door side/passenger side US)
Bank 2 = 4, 5, 6 cylinder (drivers side US)
OBDII/CAN regime dictates that Bank 1 is always the bank that contains Cylinder 1
Your fuel trim is monitored by the upstream sensor. The downstream monitors the effectiveness of the Cat.
It's 22mm
![](https://mbworld.org/forums/attachments/c-class-w203/163839d1250679441-o2-sensor-o2-sensor-22mm-socket.jpg)
P0175 = System too Rich (Bank 2)
Bank 1 = 1, 2, 3 cylinder (fuel door side/passenger side US)
Bank 2 = 4, 5, 6 cylinder (drivers side US)
OBDII/CAN regime dictates that Bank 1 is always the bank that contains Cylinder 1
Your fuel trim is monitored by the upstream sensor. The downstream monitors the effectiveness of the Cat.
It's 22mm
![](https://mbworld.org/forums/attachments/c-class-w203/163839d1250679441-o2-sensor-o2-sensor-22mm-socket.jpg)
#31
Oh yeah, and another thing...
I am going to be replacing the front struts. There are 2 kinds according to sears auto. There is the Monroe Sensa Trac and the KYB Gas Shock. Has anyone had experience changing these out?
#32
Okay, I'm going to remove the exhaust pipe!
Do you recommend removing the exhaust pipe/cats to gain access to the upstream oxygen sensors on my C240? I don't see any other way? Thank you.
#33
Super Moderator
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No - use a crows foot spanner with a long or jointed drive or a hammer
#34
Super Moderator
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Here is the genuine Benz tool for the M112 engine- Some people find a shifting spanner easier than a rachet, swivel & long drive. You do the upstream from the top & downstream from the bottom. The genuine tool is very similar to the generic that I show above.
![](https://mbworld.org/forums/attachments/c-class-w203/198599d1292798060-oxygen-sensor-clarifications-w203-c230-kompressor-mb000589710300.jpg)
The front struts are SACHS-BOGE. The only other brand I have experience with are Koni yellows
![](https://mbworld.org/forums/attachments/c-class-w203/198599d1292798060-oxygen-sensor-clarifications-w203-c230-kompressor-mb000589710300.jpg)
The front struts are SACHS-BOGE. The only other brand I have experience with are Koni yellows
#36
#37
One more question on this strut stuff. Tell me if I'm correct in needing the following:
*strut assembly front
*strut bump stop but not necessary
*shock mounting kit
*strut mount
I would think that all of the aforementioned would be included in the assembly. Do I need all of this? Thanks again and that concludes questions...
well, for now.
*strut assembly front
*strut bump stop but not necessary
*shock mounting kit
*strut mount
I would think that all of the aforementioned would be included in the assembly. Do I need all of this? Thanks again and that concludes questions...
well, for now.
#38
Here is the genuine Benz tool for the M112 engine- Some people find a shifting spanner easier than a rachet, swivel & long drive. You do the upstream from the top & downstream from the bottom. The genuine tool is very similar to the generic that I show above.
![](https://mbworld.org/forums/attachments/c-class-w203/198599d1292798060-oxygen-sensor-clarifications-w203-c230-kompressor-mb000589710300.jpg)
The front struts are SACHS-BOGE. The only other brand I have experience with are Koni yellows
![](https://mbworld.org/forums/attachments/c-class-w203/198599d1292798060-oxygen-sensor-clarifications-w203-c230-kompressor-mb000589710300.jpg)
The front struts are SACHS-BOGE. The only other brand I have experience with are Koni yellows
Last edited by enap66; 12-19-2010 at 07:55 PM.
#39
Super Moderator
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Yes - if you can get it to fit & it helps. I have always pulled the upstream sensor on the M112 from above. I have not tried the same on an M272 with the quadcam heads. Access is probably worse on that.
If you are going to sell this car you just need struts for front & any rubbers that look damaged.
If you are going to sell this car you just need struts for front & any rubbers that look damaged.
#40
Yes - if you can get it to fit & it helps. I have always pulled the upstream sensor on the M112 from above. I have not tried the same on an M272 with the quadcam heads. Access is probably worse on that.
If you are going to sell this car you just need struts for front & any rubbers that look damaged.
If you are going to sell this car you just need struts for front & any rubbers that look damaged.
#41
Yes - if you can get it to fit & it helps. I have always pulled the upstream sensor on the M112 from above. I have not tried the same on an M272 with the quadcam heads. Access is probably worse on that.
If you are going to sell this car you just need struts for front & any rubbers that look damaged.
If you are going to sell this car you just need struts for front & any rubbers that look damaged.
#42
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#43
Senior Member
Or you could just follow Glyn's advice and buy a crowsfoot wrench instead. It makes the job easy, though, as he says, you'll need a long drive extension. I bought a set of crowsfoots (crowsfeet??) to work on something Italian and find enough uses for them that I've never regretted having them in different sizes. A crowsfoot is, for example, the best available tool for the dreaded door hinge adjustment task on a Lotus Europa.
#44
Or you could just follow Glyn's advice and buy a crowsfoot wrench instead. It makes the job easy, though, as he says, you'll need a long drive extension. I bought a set of crowsfoots (crowsfeet??) to work on something Italian and find enough uses for them that I've never regretted having them in different sizes. A crowsfoot is, for example, the best available tool for the dreaded door hinge adjustment task on a Lotus Europa.
#45
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I'm delighted you are sorted. I have never had that much trouble. The damn things can seize in quite badly. Note the hammer marks on the Stahlwille crowsfoot.
#46
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2003 mercedes benz c230 kompressor silver
hi
I am a new bie....any help would be appreciated.
I have the CEL on and it is the pre-cat or upstream O2 sensor. My mechanic gave me a quote for 205$ and dealer for 315$. I found on amazon for 88$ and 102 $ down stream and upstream...
http://www.amazon.com/Bosch-16272-Ox...=pd_sim_auto_1
http://www.amazon.com/Bosch-16268-Ox...=pd_sim_auto_1
Readin through above someone mentioned the wire is short and connectors wrong... so should i just buy the down stream sensor (i need upstream) and the problem is solved or do i need some modifications on the connectors if i buy down stream sensor..please help me or point to where i can buy the correct one...
thanks in advance
ravi
I am a new bie....any help would be appreciated.
I have the CEL on and it is the pre-cat or upstream O2 sensor. My mechanic gave me a quote for 205$ and dealer for 315$. I found on amazon for 88$ and 102 $ down stream and upstream...
http://www.amazon.com/Bosch-16272-Ox...=pd_sim_auto_1
http://www.amazon.com/Bosch-16268-Ox...=pd_sim_auto_1
Readin through above someone mentioned the wire is short and connectors wrong... so should i just buy the down stream sensor (i need upstream) and the problem is solved or do i need some modifications on the connectors if i buy down stream sensor..please help me or point to where i can buy the correct one...
thanks in advance
ravi
#47
So what's the answer? Which Bosch part number is for the upstream and downstream sensors? I'm particularly interested in the upstream one since everyone said that the wire was too short. Please respond. Thanks.
#49
Thoughts?
#50
Super Moderator
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Personal choice dependent on your toolbox. The dealers do it from the top. I've only ever done it from the top. Some prefer the bottom.