aolsen

Where exactly are the oxygen sensors (02 sensors) located on a 2003 C230 Kompressor?

How can I replace them? I've been reading around on mbworld but can't find a clear answer, I do notice various people having issues with oxygen sensors.

Thanks everyone.

DuncanMB

Not 100% sure on your car - the 2003 C230 Coupe 1.8l kompressor has one on the left (passanger side of the car) side of engine above the catalytic converter sticking out about half way down the engine compartment and one below the converter closer to the bottom.

aolsen

Where does the other end of the upstream O2 sensor plug into? I tried following it with my fingers but cant seem to find it. Is it only reachable from underneath the car?

Glyn M Ruck

Take the bottom plate off & both are obvious.

aolsen

Ok, thanks!

aolsen

2003 C230 Sedan

aolsen

Well I received the oxygen sensor for my car, the specs were all correct, however it was way too short, and the connector was wrong. Besides the dealer, where can I get a direct fit upstream 02 sensor?

Ricardo Cleves

Last week I drove my 2002 C230 on a floded area (Miami Beach,Florida) It did rain a lot.
Now my car has the check engine light on and displays check ESP.

Could anyone let me know how to fix this problem?

Thanks.

SeaCoupe

The only reason I'm touching this is because you have a 2002 Coupe.

So you have a check engine light on? The first step is getting the code read. Take your car to an Autozone or someplace that reads codes for free. Then create a new thread with the OBD code and we can start from there.

Ed

tronak

Needed to replace the upstream O2 sensor on my soon to be ex-wifes car. The downstream sensor was replaced 1 year ago ... they should have changed both but given the price for the correct one i see why they took the easy way out. The catalog for Bosch at Kragen showed a #16272 $129.00 and the cable was too short (it appears to be the downstream sensor). The items are reversed in the catalgue and the rear one (after Cat) Part #16268 (Kragen $316.00) seems to be the correct one with the longer lead and the wiring connector plug snakes around the back of the engine and is actually located on top of the starter. I am told it is accessible from under the car. Regardless, this will be a pain in the *** on my garage floor.

Given the price i am going to try and shop around for the sensor and see what i can find. It may be best just to go to MB for the sensor.

I thought this might be helpful info for others.

samaritrey

i have to ask why you would fix a car that belongs to your soon to be ex-wife? every divorce i have seen ends up in the couple fighting over every last dime and thing of value. not helping each other out. i am not saying that is bad but you must be a very nice guy. and dam 316 for the sensor that sucks man sorry hope you can find it cheaper their are some good mb part sites that i could post if you want to check for a better price.

samaritrey

Parts
http://www.rmeuropean.com/
http://www.genuinemercedesparts.com/
http://www.trademotion.com/splash/in...?siteid=214660
http://www.autohausaz.com/index.html

W203E35

183.00 at Getmercedesparts.com and that's OE (not aftermarket)

Glocker

I was just informed by my dealer that my Upstream O2 Sensor is bad. Causing engine light to be on.
My question is:
On a w203 c230 4 banger, are there 2 upstream o2 sensors before the cat or only one? Do I have to replace both or the one closer to the cat?

TIA!

lars

One upstream, one downstream.

Glocker

Ok thanks for the info. I found a very good diagram that explains where the Upstream & Downstream O2 Sensors are located.


Upstream O2 Sensor is before the Catalytic converter.

lars

If you're planning to replace the pre-cat sensor yourself, you'll find it hard to fit a wrench with enough leverage onto the sensor. The job is made a lot easier with a 22 mm crowsfoot wrench, which you should be able to buy from an auto supply house.

A crowsfoot wrench looks like the very end of an open-end wrench but with a socket where the open-end's handle would start. Mine fits on the end of a 3/8 drive socket extension.

Glocker

Thanks for the info bro!

fluxemag

I got both sensors for under $100 each on Amazon. They should get here later this week. But now I've read that Bosch 16272 is too short to be the upstream. I got 16272 and 16268, can anyone confirm that these are just reversed in the catalog (making 16272 downstream and 16268 upstream)?

http://www.amazon.com/Bosch-16272-Ox...tive&carId=001

http://www.amazon.com/Bosch-16268-Ox...xgy_auto_img_b

tommy

If anyone would do me the favor after they've replaced either O2 sensor, I'm going to be working on a fix for my P0420 problem (aftermarket cat), and need to have an O2 sensor to help with how much I have to bore out of the part I'm going to be inserting the O2 sensor into to try to get the code to not come back.
Would gladly reimburse shipping - thanks.

fluxemag

Well I replaced the downstream O2 sensor yesterday. Good news is it was pretty easy. Bad news is I couldn't do the upstream sensor because the wire was too short on Bosch part 16272. The downstream sensor had oil in the connector (the electrical connector, not by the sensor). I guess this is because of the manufacturer's defect with the cam position sensor (which is free to fix at the dealer even if you're out of warranty). I will be calling to have the service campaign done for the cam sensor leak and hopefully be reimbursed for the O2 sensor cost.

So you can have my sensor, but the connector has oil in it and the sensor is bad...

I used q-tips and IPA (not the beer) to clean out the oil in the socket connector after I noticed oil dripping from the old sensor connector. So far no CEL, but it still shows Not Ready on the OBD scanner because not all tests have been performed.

DuncanMB

The CEL takes a bit of time to come up due to some specific engine/load cycles required. Hope your dealer is cooperative on the cam leaks.
My car show P0130 on ODB (and on output from the sensor) and I am installing a new upstream O2 sensor this week although this one was changes by the dealer only 40000 miles ago.
Is anything other than the CEL reset required after installation?
I have read about adaptation etc. but have no idea what it entails.

Thank you

lars

I have to say I don't see how oil from the leak at the cam seals, which are on the front of the engine, could get all the way down to the electrical connector for the downstream O2 sensor. Might there be a different leak at the back of the engine?

enap66

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!

enap66

Also, can anyone tell me if I need a bosch or will something like this work?

http://www.autopartswarehouse.com/mm...sor~parts.html

Go down to just about half way and you'll see it for $59.41, list price $70.10. I bought a MAF once that wasn't bosch and I had to purchase it from bosch afterward making it a waste of time and money. I want to make sure I could purchase this one before I do, and I'm assuming that some of you would know the answer to this question. Thanks!