Blew out o2 sensor, threads gone.

[joeybuddy96]

Accelerated from zero to 40mph too fast. Now the o2 sensor is dangling loose, and I can hear the exhaust exiting the empty socket. The threads on the o2 sensor are *gone* gone. I'm thinking the threads on the inside of the socket are probably completely ruined. I assume if I were to look in the socket, I'd see that it's gone from rifled to smooth bore.
I think the threads probably got stripped out when I was getting the last one un-seized. Back when that was going on, the mechanics had to use a torch to get it out. I'm guessing they might not have used a thread chaser on what few of the threads were left intact. The pressure from accelerating too fast probably just broke the remaining threads and shot the o2 sensor out past the stripped threads.
The heck am I supposed to do? I'm going to smush some steelstick on there with the ruined sensor until I can get a new o2 sensor. I think I'll have to get an o2 socket thread chaser, but I don't think that'll do any good since there probably aren't any socket threads left (I doubt the overpressure rapidly unscrewed the sensor).
If I were to take it to a mechanic, they'd probably angle grind the socket off and welx a new one on, but that's probably going to cost a fortune. The bolts that hold the exhaust Y-pipe on are seized up, too, so I'd be paying even more to get those off. It'd be a long job for mechanics paid by the hour.

 

[cobrajeff96]

Usually 15-30 seconds worth of direct propane to a nut/stud will allow it to be turned loose. Failing that, acetylene but only for a few seconds. Best is the induction heater, the gun with the thick coil on the end of it.

It is not expensive at all for someone to slice off and weld on a new threaded O2 bung. Shouldn't be anymore than $100 and that's being generous.

 

[joeybuddy96]

@cobrajeff96
I'll have to try the induction gun next time I have to remove seized o2 sensors. The downstream right side sensor was a nightmare to get out. I rounded it off and had to pay like $300 for a mechanic to remove it. It took them several hours to get it out.

I hope it'll only be $100, but since the clearance is so tight and the position of it is so hard to get to, idk if they'll be able to get a dremel tool up in there, let alone an angle grinder.

This might be tangential and unnecessarily massively overcomplicating it, but the exhaust manifold nuts are seized up and two of them are rounded off, so I can't really remove it from that end. It takes a long ratchet extention to even touch those manifold flange nuts, so it'd probably have to be a dremel tool to cut off the nuts; the studs are probably rusted solid and seized up in there, too. The technique with stacking two nuts on top of each probably won't work because the tight clearances prevent getting enough leverage on a wrench. I think it has to be a socket. I used just my own upper body strength, but I think I used a 16mm instead of a 15mm and that's what rounded it off ((along with the nuts dissolving into a smaller size because of rust), it could also have been because the nuts are made from metal that's softer than butter, too). If I do the stacked nuts thing wrong, I'll just have another rounded nut on the stud. Channel locks on the end of the stud might work if the metal is hard enough and if I could somehow get enough leverage but it's just so tight that I can barely reach it with my fingertips. If I dremel the nuts off, I could disconnect the whole freaking exhaust manifold and replace the studs from there.

I thought maybe the mechanics could be able to disconnect the end of the manifold that connects it to the flex pipe to lower it to give them more room, but I don't think it'll flex any.

I guess they could potentially use a reciprocating saw to cut off a whole section of the Y-pipe, disconnect it from the flex pipe, angle grind the old socket off, weld the new o2 sensor on, and weld the Y-pipe back together.

 

[cobrajeff96]

Yea, there's always a way. Just depends on how bad the problem is.

 

[duh09]

An exhaust shop would more than likely just weld that fubar'd hole up and just drill and install a new bung beside it rather than trying to cut that one off and get it back in the exact same position. It should not be expensive. I think I've paid like $40-60 for getting a bung welded in - I've done it on a 05 RSX that I wanted to add another wideband to and a 74 Vette that we added FI to and neither were an ordeal. I went in with the O2 bung in hand just to make sure they had one, they're $5-6 I think.

 

[96blak54]

Dang exhaust work!

Sadly, there isnt much offering for cat pipe replacement like a X-pipe or H-pipe or Id suggest buying one of them and swapping it in.....it would have fresh o2 bungs and cat delete! Looks like you can get a new catalytic converter Y-pipe replacement off rockauto for like $400.

Im with @duh09! A good muffler shop would have zero issues correcting your problem, but its gonna cost. Im sure they charge over $100hr.

You have this option


Grind off the original bung smooth with the pipe(if possible)
Clamp this on and either align with hole or orientate new location, drill the hole.....BAM.....new bung.

 

[96blak54]

@joeybuddy96 where you located in Ky?

 

[joeybuddy96]

@96blak54
If I could angle grind it smooth enough, that'd work. The problem with the right downstream socket is that it's pointing almost straight up towards the frame of the car. I haven't tried it myself yet, but trying to do that kind of fine work with like zero clearance, without leaving a raised piece of metal is probably going to take hours and be difficult. I can see myself easily making it worse, or making it less than airtight (thay muffler tape stuff and high heat steelstik would help some, though). I'm not opposed to the idea, especially if it'll save me several days worth of my wages.

The tight quarters and bad angle are part of how I ended up rounding off the original o2 sensor and having to take it to a mechanic to get it out, and I'm assuming at some point in that fight, it ruined the threads enough that the pressure pushed it past some damaged threads.

Louisville, KY.

 

[joeybuddy96]

I've been driving around with the temporary steelstik fix for several weeks. I could hear some rattling a couple days ago. Checked it today. The steelstik epoxy is still attached to the o2 sensor, but detached from the exhaust pipe, so it's definitely not a long term solution. Maybe exhaust tape would be better, but if I want to get the new bung on it, the tape would get in the way and make that job longer and consequently cost more.

I still have to take it to a mechanic, but the transmission pan appears to be leaking onto the o2 sensor, so I'd rather fix that so I'm not having to buy a new o2 sensor once a week or smth. That, and I'm busy trying to fight with the brakes rn.