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removing o2 sensor

1601 Views 15 Replies 10 Participants Last post by  Zeemax
I can´t get it off the exhaust manifold. It´s the stock OEM o2 sensor (I think) and I really hope it´s not welded onto the manifold.

I haven´t been able to get that much torque on it because it´s at such a godawful weirdass angle and the crossmember and radiator are both in the way... argh. what tool should I use? How do I get it off?

Also, how do I properly probe the O2 sensor (WITHOUT SHORTING IT) to measure the output voltage? I need to tune the idle mix because I put on the RX-7 VAF. Thx.
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If i remember correctly , there is a socket made for this purpose, however i don´t remember where to buy it. You should be able to probe it at the connector underneath the distributor(someone correct me if i´m wrong.
Ahem, I tried a spark plug socket, and that almost works for the stock sensor, but I know I wouldn´t be able to put on the bosch sensor because it´s a little longer and fatter.

Also, I know that the wire leads up to a connector by the dist, but I´m not sure HOW the probe it (like where should I place the positive and negative probes of the muiltimeter...)?
Be careful taking the 02 sensor off the maifold because when i tried taking it off my manifold i ended up cross threading it so i had to take the whole manifold off put it in a vice and cut the wire off the top and put a wrench with a long pipe on the end of the sensor and force it to come out. I was a bitch. Yeah there is a socket to get it off but the only place i have ever seen it was at this place called Clark Tool. Good luck and have fun. :-D
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01-03-2003 at 20:52, Trashknight wrote:
Be careful taking the 02 sensor off the maifold because when i tried taking it off my manifold i ended up cross threading it so i had to take the whole manifold off put it in a vice and cut the wire off the top and put a wrench with a long pipe on the end of the sensor and force it to come out. I was a bitch. Yeah there is a socket to get it off but the only place i have ever seen it was at this place called Clark Tool. Good luck and have fun. :-D
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Do they have a surgery for that now? LOL... sorry I couldn´t resist. :-]
Place the negative probe on the battery negative and probe the o2 sensor with the positive probe. I´ assuming the your car has the single wire O2 sensor.
use some copper anti-seize paste when installing the new 02 sensor to ensure it can be removed easily next time.

PB Blaster is one of the best liquid rust breakers there is, so you may want to soak in a bit of that (cold manifold only)

Then you may want to use a propane torch to heat up the manifold, but not the sensor itself (again, start when the 02 sensor is nice and cold).. this should cause the kind of thermal expansion you need for it to break loose.

You´ll want an 02 sensor socket because the slot in it allows the wire a place to go during installation. It´s fairly easy to just cut the wire on the old one so you can throw some extra torque into it with a standard closed socket (like your sparkplug socket).

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I haven´t been able to get that much torque on it because it´s at such a godawful weirdass angle and the crossmember and radiator are both in the way... argh. what tool should I use? How do I get it off?
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You tried a good ole breaker bar w/ a pipe extension yet? Most breaker bars can be swiveled along one plane, so the awkward angle shouldn´t be too bad.. then again, I´ve yet to pay any attention to the 02 sensor in my LX, so I can´t visualize the obstructions you´re referring to (shots in the dark here, sorry) :-]
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First off this is how you prob an O2 sensor. DO NOT put the negative prob to the Batery. The O2 sensod is an Galvanic battery that DOES NOT rely on power from the cars electrical system. It produces it´s own voltage. First off USE ONLY A HIGH IMPEDENCE DIGITAL VOLT METER to measure the voltage of your O2 sensor. Like I said, the O2 sensor produces its own votltage, so putting a low impedance or analog meter on it could short it out and render it useless. You SHOULD put the + probe into the CONNECTOR of the O2 sensor, and the - probe to the OUTSIDE CASING of the sensor.

As far as removing the old sensor, they are hard to do on a rust free AZ car, so I can just imagine how hard it will be for a rust queen NY driven car. You will need to get some penitraiting fluid. WD40 probably won´t cut it too well in this situation. The PB Blaster Beav recomended is some really good stuff. They sell it at Checker Autoparts out here. If you have an Advance Autoparts out there they should have it too. Also I have seen the special sockets at Checker as well, so you might want to check the tool isle at Advance or even Auto Zone or Pep Boys. I personaly just use a box end wrench. And as with all stuck fasteners, leverage is the key, so the longer the wrench, the better. Cheater bars are nice too. Also, Anti-sieze is a must if you want to be able to get that thing out the next time you need to replace it. A lot of the bosch O2 sensors come with it already on there, but open the package and make sure fist. You should put a little anti-sieze on your spark plugs when you put then in too.
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Ok this is easy. Remove the radiator take off that ugly heat shield and put the car up on ramps in the front. follow the o2 sensor line to where it ends up at the connector. Take that connector apart and slide a box end wrench down the wire. Make sure that the box end wrench is long. The wrench size is 7/8. Btw new oxygen sensors come with antisieze compound. This is not as hard as everybody has put it out to be. It is a 10 to 40 minute job depending on which oxygen sensor you buy. If it is the direct plug in one then 10 minutes and your done but if it is the universal other stuff is involved in this. Btw you should never cremp a o2 sensor line it will throw off the voltage you should sauder using low impedience sauder. I did this and let me tell you it is a pain you might want someone to help you sauder because it is hard to hold two wires together and sauder them at the same time and they take forever to heat up so the sauder can melt on them. Btw when done use a shrink tube on the wire where you saudered because the wire is supposed to be air tight.
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Just when things couldn´t possibly get any worse...

I still couldnt get the O2 sensor off, after repeated attempts, so I took it into the shop and let the real mechanics play around with it. They somehow managed to get the o2 sensor out, and then proceeded to put in my brand spanking new bosch sensor in.

Low and behold, they completely fuck up my new bosch sensor, and the manifold. So it looks like I´m back to square negative 2.

So now I have to buy a totally exhaust manifold and o2 sensor, whoop-dee-shit. :-Y :-Y :-Y :-Y :-Y :-Y :-Y :-Y :-Y

Questions:
1. What is the difference between the exhaust manifold, the exhaust header, and the downpipe?
2. What manifold/header/downpipe should I get to replace it?
3. Should I just say damn it all to hell and turbo my ride, even though it´s got 133,000 miles on it and just drive it until it dies 5,000 miles later?

This sucks ass.
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If the shop messed up your manifold and O2 sensor they should be the ones buying the new components. I´d be pitching a fit till I got new parts. But if you fee like taking it up the ass, then your best bet would be to go to the salvage yard and try to find a new manifold. Turboing is up to you, I just hope you know what your getting yourself into.
Well I usually don´t take it in the ass, but I was considering getting a new cat-back and cat, and I honestly think it´s a huge pain in the ass that they fucked everything up because now instead of buying a new exhaust, I´ll be paying to fix what some dumbfuck messed up.

But if you were me, and you wanted to upgrade to, lets say, a GENIE header, then what would you do? Would you make the shop pay for the cost of the menifold they messed up (probably worth like 15 bucks anyways) and then the full price of the o2 sensor they messed up?

I think that would be fair, because even though I understand that they could have messed up the manifold when they took the old o2 sensor out, they should have realized that the new one wasn´t going to go in and just replaced the manifold since they messed it up...

But instead, they fuck up my brand new o2 sensor, and that isn´t acceptable.

So whaddayasay? Make em replace my bosch o2 sensor, and they give me a modest 10 or 15 bucks to replace the manifold they messed up, so I can use it towards a genie header?
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06-03-2003 at 08:25, siragan wrote:
So whaddayasay? Make em replace my bosch o2 sensor, and they give me a modest 10 or 15 bucks to replace the manifold they messed up, so I can use it towards a genie header?
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Siragan, that sounds reasonable to me. Only fair they pay for what they messed up.
I´d say is reasonable.

Almost forgot:
Exhaust manifold is completely = Header
Downpipe is not the same. Downpipe is the exhaust piece that bolts to the side of a turbo and goes to the rest of the exhaust system.

<img src=http://mercury.pr.erau.edu/~bladej/escortweb.jpg>

Jason Blade, 93 EGT Turbo

[ This message was edited by: TheBlade on 06-03-2003 11:28 ]
Okay,
My GT is kinda old and rusty, it has 133K miles on it...

should I get a stock exhaust manifold (about 100 bucks) or should I really binge my money and buy that expensive corksport genie header? Will the genie really make any difference?
Think I read somewhere else here that the Genie didn´t really do a whole lot. The Pacesetter gives you an extra 4 lbs/ft torque but you have to live with people calling your Pacesetter a shitty product.
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