Im having a hell of a time removing the oxygen sensor from my exhaust manifold. I dont have a wrench that fits it, and the crescent wrenches cant get a good grip on it. Can anyone tell me what tool to use to get it off?

 

I think a flare nut wrench might do the trick. You might have to use a breaker bar, cause those things are pretty much melted to the primaries. Atleast mine was.

A useful tool that I have is a 2 foot 1" lead pipe, with a 1/4" groove cut in one edge of it, this allows it to slip onto open end wrenches and lock tightly, so that you can give extra torque to removes things. BTW, the flarenut wrench is like a 6 sided wrench, except it has a part missing so that you can slip hoses and wires into it and still have 6 sides of the bolt to lock onto. They are very cheap, and a good addition to any tool collection! Good luck.

 

What size flare nut wrench? I couldn't find one big enough for the O2 sensor. I think its 20 or 21 mm but im not sure. I just wanted to know what size for sure before I went out and bought the wrench.

 

You know what, I'm not sure what size it is, I have a spare one in my basement but I'm too lazy to go check. I think they have sockets especially for o2 sensors though. It's like a deep socket with a hole in the side of it like a flarenut wrench. You're local autoparts store should carry it. Besure to use anti-seize compound on it if you re-use your old one.

 

Hold up a sec and I'll go check and see what size it is.

 

7/8". There is a special socket with a slit in it for the wires.

 

Well I'm not sure about what size it is in metric, but in standard it's 7/8. Hope this helps you some.

Edit: Ahh, I should have reloaded the page before posting. Sorry all.

 

I tried a 7/8 wrench, but it seemed really loose. Maybe the socket will have a better grip than the open ended wrench. I'll go to NAPA tomorrow and see if they have it. Thanks.

 

Yah, mine seemed loose too, but it's the only one I could find to fit. Maybe you can find a metric tool that will fit more snugly. Since the car was engineered in Japan, I'd think that metric sizes would fit better.

 

use either a 21 or 20mm wrench or there are oxygen sensor sockets specially made to remove these. the sockets have a open slot on one side to allow room for the wires. i'd advise you to disconnect the electrical connection before you take out the o2 sensor so you don't twist them and cause a short in these wires will make you hate life.

use a ruler to find the correct size... or check your service manual. you don't have a service manual? get one! shoe!

 

Lol, definately get a service manual, or atleast a Haynes manual. Or the god Helms. Is there an easy way to relocate the o2 sensor? Because when I put my header on, I just extended the wires and it's been throwing a code ever since. The car runs fine, and no power loss or anything, but it's still weird as hell..

 

I either use a 22mm or 7/8" end wrench, works just fine and shouldn't round off your oxygen sensor unless it's messed up to begin with... When it's been real tough I've had to drop the exhaust and put a pipe wrench on the lil ******... Still worked tho... Good Luck


Modified by Kataku2K3 at 9:15 AM 5/14/2003

 

you can buy a O2 sensor socket for about $10 at any autoparts store. I think autozone even rents them out for free. thats the best way to do it

 

The special socket with the slit in the side will just spread apart with a frozen O2 sensor. I've been frustrated, cut the connector off and used a box wrench on them with a pipe, darn if I didn't shatter the craftsman box. It was like a foot long too.

The only successful way I have found is the "heat wrench" The oxy-acetylene torch on the bung, then the split socket, or a tube wrench or sometimes just an open end wrench will get it off. They are a _itch.

Regards,
BigMoose

 

Open-end 22mm and a hammer with some PB Blaster.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BigMoose &raquo;</TD></TR><TR><TD CLASS="quote">The special socket with the slit in the side will just spread apart with a frozen O2 sensor. I've been frustrated, cut the connector off and used a box wrench on them with a pipe, darn if I didn't shatter the craftsman box. It was like a foot long too.

The only successful way I have found is the "heat wrench" The oxy-acetylene torch on the bung, then the split socket, or a tube wrench or sometimes just an open end wrench will get it off. They are a _itch.

Regards,
BigMoose</TD></TR></TABLE>
The el-cheapo O2 sensor sockets are no good for removing the O2 sensor, they work o.k. for installation. I have a Mac o2 sensor socket that works on most sensors, the slit is narrow. If I am going to replace the sensor anyway, I cut the wires and use a closed 7/8" socket. Heat certainly does not hurt when it comes to getting a stuck sensor out

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BigMoose &raquo;</TD></TR><TR><TD CLASS="quote">The only successful way I have found is the "heat wrench" The oxy-acetylene torch on the bung, then the split socket, or a tube wrench or sometimes just an open end wrench will get it off. They are a _itch.
</TD></TR></TABLE>

You could just run the car for about 5 minutes, assuming you still have the manifold/header still on. NEXT TIME, that's what I'm going to do.

How many stock Honda exhaust manifolds you think are sitting in people's basements with perfrectly good $150 O2 sensors stuck in them?

 

What works REALLY well is to run the car for a bit to heat it up,
and then use a vise-grip.. I'm guessing you're going to replace the sensor?

So what if you screw up the edges.. just use the vise-grip to torque it back on
later...

 

Of course I have the helms manual for my car. I never work on my car without it. But it says nothing about the size of the 02 sensor. I went to napa, picked up a socket and it came right out. Thanks for the help.

 

Does anyone know if Craftsman makes an O2 socket for our cars?

I found this one on their site:

&gt;&gt; $10 at Sears &lt;&lt;



These things have been a bitch in the past with regular wrenches and $hit! Would like to pick up a decent O2 socket for future use

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BigMoose &raquo;</TD></TR><TR><TD CLASS="quote">The special socket with the slit in the side will just spread apart with a frozen O2 sensor.</TD></TR></TABLE>I've got a O2 sensor socket that isn't slotted thru the side. Instead it's got a groove inside (not completely thru the wall) where you can lead the wires down alongside the hex part. I probabaly got it at some AutoZone-type place, but I can't remember where.

 

Can anyone confirm the $10 tool above? Looking to pick one up to avoid future head aches

 

Yes it works very well ive used it on many occasions. There is also another tool that works just as well its kinda hard to explain cause i cant find a pic but its an end of a wrench with a 3/8 slot next to it so you can use a ratchet.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CBRF4i &raquo;</TD></TR><TR><TD CLASS="quote">Yes it works very well ive used it on many occasions. There is also another tool that works just as well its kinda hard to explain cause i cant find a pic but its an end of a wrench with a 3/8 slot next to it so you can use a ratchet. </TD></TR></TABLE>

its called a crowfoot

 

snap-on part # YA8875
retail price is $28.95
it's a 3/8" drive impact crowfoot with a slit for the O2 wires. bought one like 2 years ago, and i use it at least twice a week.