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Detached oxygen sensor

Does a detached oxygen sensor (by the catalytic converter?) pose a danger because of fumes going into the cabin through the floorboard?

Background story: I was accelerating with the ECT power button on, when the 02 sensor apparently was blown off but was still held on by electrical wires. Took it to a dealership which said the 02 sensor was damaged and needed to be replaced to the tune of almost $400. I said I’d think it over, and they let me take the truck home without re-inserting the ‘damaged’ 02 sensor. They did advise me that the fumes were ‘blowing into the floorboard’.

Took my truck to my trusted mechanic, who reattached the 02 sensor, tested it and said it still works. He charged me $30 bucks.

My follow up question is, did the dealership put my safety at risk just to make dishonest money?


OK, no one is biting. I admit it’s a touchy subject, so if anyone would just give an objective opinion about my first question, I’d appreciate it.

Was the dealer’s estimate based on replacing the catalytic converter and sensor? And likely the independent shop repaired the old threaded base and reinstalled the old sensor with success. Dealerships have outrageous overheads that their shop pays. Comebacks are a terribly expensive problem. Dealerships find it much more profitable to make everything ‘like new’ with a great deal of profit in doing so compared to ‘fixing’ the problem for a few bucks and hoping the fix holds.

The quote I received from the dealership was only for the installment of a new oxygen sensor.

Do you have any opinion on the possibility of fumes getting into the truck cabin? Should I have been concerned about safety?

Thanks for the reply, BTW.

With the O2 sensor out of the socket, exhaust WILL blow out of the hole. If it hole is aimed at the floorboard, it WILL blow onto the floorboard steel. In that, they did not lie.

Only if the floorboard has open holes in it, with any plugs that were removed, would the exhaust fumes get into the cab. Driving with the windows wide open would help prevent any fumes from injuring you, but you shouldn’t run like this for anything but a very short drive to a mechanic. Which you seem to have done.

The dealership did not ‘put your safety at risk to make dishonest money’. Faced with the situation, I would have also advised you that the O2 sensor may be damaged, as well as the socket in the exhaust, and quoted you a price based on that. The dealer is less likely to trust a visual inspection of the sensor to determine it’s condition and just replace it. After all, it blew out for some reason, and the old sensor could blow out again for the same reason later.

I thank you for your answer. You’ve indeed put the dealership’s action in a more logical sense.

I understand business(especially big businesses) have to make a profit. That’s just the way it is, especially in this economy. It is up to every individual to educate himself, find out all the choices available to him, and ‘live’ within his means—which is what I did.

We are getting only the part of the story that puts the Dealership in the darkest postion and places the independant mechanic in the position of a saint. We are being set-up here.

When one speaks of an oxygen sensor being “detached”, too me it means a wire is simply disconnected (how this would happen with the locking type connector used is unclear) but your post goes on to describes what seems to be a sensor that has been blown out of its threaded boss. If a sensor is blown out of its threaded boss it is easy to see how expensive repairs may be justified.

I do not at all see what your intentions are by trying to get someone to agree that the Dealership somehow put you at risk. If you want to leave with you car you are certainly free to leave.

How long did you drive it in that condidion before you toook it to the dealership? You apparently survived that long, so the dealership just gave you your truck back.

Would you have preferred they require you to tow your truck away?

For $30 I don’t suppose your trusted mechanic took time to inspect the threads of the receiver hole in the converter or on the sensor? A piece of information is missing. I’d be curious to know if indeed the threads took damage, in which case, you may very well end up in the same position not long from now.

On the other hand, $400 to pull down the converter, weld in a new receiver and replace the sensor doesn’t seem overtly unreasonable. But, again, missing pieces.

O2 sensors don’t just fall out. Weak threads, exhaust restriction (clogged converter) leading to blowing the O2 out, etc. are possibilities.

Hopefully this reattached O2 will stay reattached but it would be interesting to know the details behind the 02 coming out and even more importantly; how it was reinstalled.

It is never safe to have any exhaust gases leaking out from underneath your vehicle.
Would I drive it that way 10 miles to get it fixed - sure.
Would I drive it that way for the long term - definitely not.

First of all I’d like to thank everyone who posted their thoughts on my inquiry.

Secondly, I’m the least knowledgeable person I know when it comes to cars, so I’m not in the position to explain the technical details of this issue. I’m posting purely from the standpoint of a customer. So when I asked about the possibility of my safety being put at risk, I really meant my family’s safety, as this is a family vehicle. I’m not trying to make anybody agree with me about anything. I was soliciting people’s technical expertise to shed light on whether or not my safety concerns had a basis OR NOT. The general consensus is there is minimal health/safety risk by not resituating the ‘damaged’ sensor—then great!

Based on everyone’s combined opinions, I now believe that there was no malicious intent on the part of the dealership’s actions, that it couldn’t have proposed any other solution to my problem, except to ‘fix like new’—it couldn’t put a ‘proper’ guaranty/warranty on the work they do, otherwise, right? I understand that.

I hate to go on a bit of a tangent, but I see this topic as being like having a medical problem. If you go to a general physician, he might prescribe medications. A surgeon will cut. An alternative medical practicioner…you see what I mean—I just had to find a solution that I could live with (a little pun intended :wink:

It wasn’t my intention to malign dealership mechanics, or dealeships for that matter. I’ve gotten my answer to this issue to my full satisfaction.