I got my downstream oxygen sensor today because it needs replacing. I've found it and I have an oxygen sensor socket, but damn me the thing is CRANKED on there. I just cannot get it to budge one bit. The engine was warm, which is supposed to help it a bit, but I fear that if I push any harder (although I've pushed VERY hard) the exhaust system will fly off. Any tricks on what to do here? I have antiseize which I'll put on the new one; too bad it wasn't on this one currently installed

 

The exhaust won't fly off, it's steadily held by 4 bolts at the cat, and three more on the y-pipe. Put some elbow grease into it. If you still can't get it to budge with all your might use the help of your friendly hammer on a wrench. A bit neandethral, but it works.

 

Thanks - I am going to try and hammer the end of it if I have to. I was also told to try PB Blaster - apparently it's the best penetrating oil and some have had success letting it soak in for up to 1-2 days on an O2 sensor prior to removal. It's going through now and I'll see if it helped at all in a few hours with the hammer

 

Spray the cold pipe with WD-40 or penetrating lubricant and let it sit for a few minutes and get a box wrench in I think 21 or 22 mm...I just checked mine the other day and it worked fine.

 

Forgive my ignorance, but what is it held on by? A bolt? Screw? Have you tried a breaker bar or an impact wrench?

 

the sensor has it's own threads on it...mounts like a bolt would feed into the pipe regardless of location ...

 

...this is either Co2 or Freon or something that turns really (REALLY) cold when it's sprayed from the can...used by electronic technicians to troubleshoot circuits that are exhibiting some kind of temperature sensitivity (fail when hot) and with the exhaust pipe hot, spray ONLY on the 02 sensor.

Remember your high-school physics...make sure u spray on the sensor itself....not on the surrunding area of the pipe because what you wanna do is leave the pipe as hot as you can (expanded) and the sensor itself as cold as you can (contracted). Spray enough to cool down the sensor as much as u can, then try it.

In my younger days, years broke loose many bolts from many motorcycle cases doing the inverse...heating the case around the offending bolt

 

Well after soaking overnight and using a little elbow grease this morning I'm still left with this stiff buggar on the car. The final step before admitting defeat and bringing it to the dealer is to torch it, so I've bought a torch and will give it a go tonight. I feel that I have a good chance with the torch. If I strip the threads or can't do it I'll just try and pretty everything up and bring it to the dealer and pretend like I don't even know where the darn thing is located.

Actually not the dealer. They want like 2 hours labor for the thing. I have another mechanic I've used. With the right stuff it should be a quick job; I fail to believe that Nissan put any antiseize on this from the factory.

 

these are easier to take off when hot vs cold. just be carful not to burn yourself. If you can do as the earlier post mentions (cooling the sensor itself while the pipe is hot/warm), that would be ideal. however, i have always been able to get them off with the proper O2 sensor socket. drive it and let it warm up. shut off and let sit for about 5 minutes just to get the exhuast to a 'reasonable' temp and remove. again, watch youself so you don't scorch yourself.

 

Spray it down, then put the ratchet on it, and find the longest PIPE you can that will go over the ratchet handle. Use that for leverage. It'll come off easy as pie.

 

You guys are right about the leverage - when I got my new 15" long handle the thing came off like a breeze. Course now we have the problem of the fact that the Bank 1 Sensor 2 that I got from nissan yesterday is the wrong freaking sensor. The plug is too big and doesn't fit with the socket on the car. I specifically asked for a Bank 1 sensor 2. Oh well, back to nissan tomorrow. Imbeciles.

 

a trick that works 4 me is like stated above use a longer wrench for more torque, but when thats not enough u can use another box end wrench (on the opposite end of the wrench ur using to remove the sensor) which basically doubles the torque and easily breaks it loose, just be careful not to let it slip since its not stable as a single wrench.

 

best to ask to look at their screen of the exploded view of the parts and point it out exactly...

 

I saw this mentioned in a couple of forms but I'll reiterate, leverage is key. I slipped a 3/4" piece conduit over my 3/8s ratchet and with a little muscle it broke loose. Just my 2 cents. -Mike

 

Nah, let's wait another 20 years.

 

 

time is flying....phew..... wonder what the next 20 year will be like... especially for cars...

 

I wonder if he is still trying to get it off.

 

the main thing you want to do is cut the wires and put a 6 point deep socket on it, impact preferred. never use a wrench or those split O2 sensor socket, they flex.

 

good to know, thanks for sharing that knowledge

 

If this thread was from 2002, and this forum is about 2000-03 maximas, wouldn’t the oxygen sensor be under factory warranty?

 

any/all special o2 wrenches are junk
cut the wire and use two normal, high quality wrenches, use the round part
lock them together and pull as hard as you can
i tried everything before this method and this was the only way, it was on there with like 300lb/ft torque, i thought i would rip the entire exhaust out

oh yeah, and i tried the impact socket w socket wrench method, broke two good ones, 3/8 & 1/2in both blew to pieces

 

I finally got the sensor off last weekend. I've been working on the darn thing since the thread started!

Actually, I did end up getting a breaker bar and it made all the difference. No heat, PB Blaster or any other such tricks required. Popped right off with the extra leverage per my December, 02 update

 

It was within 36 months but the car had if I recall 37k at the time or 37500 something like that. I thought that the O2 sensor was not under powertrain but just bumper to bumper. If it was under power train at the time I really wasted a lot of stress over it didn't I?

 

Yep they do flex some especially the cheap ones!

 

Using a torch if you have one -heat the nut (bung) where the O2 screws into know as the bung - this will expand the nut (bung) allow easier removal of O2 sensors / ( if no torch use a propane torch which almost certainly everybody has for soldering just takes a little bit longer to heat up the bung ! Works every time / remember anti-seize the new threads

 

I always cut the wires off and use a 6 point impact socket.

a few months ago I had to change one of a G37 coupe and I actually cut the main part of the sensor off leaving the hex so a short socket would fit. that I used the open end of a wrench to tighten it down.. they don't have to be put on super tight.

 

newbie necroposted like a ****, don't encourage him lol