BenzoNY

My engine check light came on last week so I took the car to the dealer and was told the O2 sensor was faulty, so they replaced it yesterday.

So I am driving around today and the damn thing come back on. WTF? and no its not the fuel cap.

tanktube67

what's the mileage on your Saks?

RLE

<<My engine check light came on last week so I took the car to the dealer and was told the O2 sensor was faulty, so they replaced it yesterday. So I am driving around today and the damn thing come back on. WTF? and no its not the fuel cap.>>

It probably isn't the oil filler cap either. The car has four oxygen sensors, BTW.

MB_Forever

I feel that sometimes the dealer just guesses when fixing a problem just so you can take it in again

stephensong

Try another dealer.

BenzoNY

Around 2400.


I know there are more than once sensor but what the likelihood that they got the wrong one? or can they all be busted?

On my Linc Aviator the engine check came on after about 25K miles and it was due to the O2 sensor as well and it was all taken care of within 2 hrs of the first visit.

CinOttawa

My brother had a chrysler sebring on which the check engine light went on, and he must have taken it to the dealer atleast 5 times. They were never able to fix it, but they managed to change everything they 'guessed' they can change. It was all under warranty so they couldn't care less, and the light would go off for a day or two and then come back on, it must be that they reset it after they do their 'guess'work. Finally, his car got stolen.

Good luck on your problem....

BenzoNY

Thats is exactly what is happening to me, it goes on and off.

chilledbenz

It could be they forgot to clear the computer codes after fixing it the first time. Been there done that, but with BMW and not my MB dealership.

MBTex

Chilledbenz your pic is very distracting, in a good way...

BenzoNY

If they didn't clear the computer I wold have seen the light when I got it back.

Krytech

I just had a defective O2 sensors on my Endeavor and when I called the dealer they first suggested, among other things, to check the air flow into the engine to make sure there wasn't a bunch of leaves or something partially blocking the intake. Just a thought...long shot.

tbenz

the dealer did not guess, they have a computer they hook up which gives them fault codes and has a test procedure to follow, just bring it back they will get it fixed have some faith. they just fix them they don`t build them

BenzoNY

well, I called up the dealer yesterday and had a talk with the manager. He asked me to bring the car in as soon as possible but I told him I can not be making trips to the dealer everyday, then he offered to pick it from my work place (50+ miles from dealer) and drop off the loaner.
So I got up this morning ready to leave for work... start the car and the car jerks rather hard. I turned the ignition off and it restarts fine. Then I drove straight to the dealer and had long talk with the manager and drove off in a C230 loaner.

What could be reason for the jerk guys? Things are getting bad to worst.

oblu

Had a jerk with a loud bang with my transmission sometimes when I first got it. General consensus was quite a few people experienced it to varying degrees.

Mine went away.

Mention it to the dealer. But it might help your blood pressure if you not worry about it too much until something actually strands you. Then it's time to worry. CEL is the default warning light now so as long as the car runs fine, just take it in when it's convienent.

Baron Samedi

Fault codes are not always a guarantee of component failure. Something in the FI or ignition is likely to be causing the exhaust stream to go out of specification range (very narrow) and the O2 sensor can't swing it back. The underlying cause is probably the reason you felt a "jerk" on startup.

What do you mean by a jerk? A stumble when you stepped on the gas in drive after starting, a misfire upon starting before being placed in gear? Additional info will help the techs diagnosis as well.

Give the techs a chance. They'll get it. Wonder if they test drove it after the repair though. How long did it take to come back on?

BenzoNY

"A stumble when you stepped on the gas in drive after starting" That would describe the scenario, but rather rough one.

The main reason I am a bit more upset than I would normally be is because I don't feel they checked everything properly. Upon initial visit to the dealer I spent roughly hour and a half there. The car remained in the drop off zone for the first half hour then got driven off and I spent the last 15 min talking to the service rep after the car came back (The sensor had to be ordered so I was set another appointment date). This leaves a 45 minute window for running all the diagnostics. I know they follow certain procedures but do you think that 45 min would have been enough? (and I know it really wasn't 45 min, probably too them 10 to 15 min just to get to the car)

tbenz

you may want to tell the manager you want them to get mercedes involved, they have a tech support they can call

Baron Samedi

You're right. They short-cutted it. But I suppose that's to be expected. Most often, an O2 sensor fault indicates a failed O2 sensor.