Shirleyda4runner

So, I was driving back home for easter from Georgia Southern University, when 20 minutes from home I start to hear this whizzing sound when I got into the 3-4 thou RPMS. The CEL didn't come on till I was literally on my street. It actually sounded like I had a hole in my exhaust, boy was I right. Apparently somewhere along the 3 hour trip the NUTS that hold the O2 sensor to the exhaust system came undone, allowing the sensor to come out and hang by its cord for god knows how long. Undoubtedly I am going to need to replace both the nuts and the gasket that keeps the two airtight. My only question, Is a junkyard the only place I can go to replace these things? Or will I have luck finding the bolts at Lowes? (And if so can someone find out what size the bolts are) The gasket is the only thing that seems like it would be a hard to find item... hmm.

Weird huh, that BOTH nuts would come off, I wonder how loose they were from the beginning. I'm pretty sure this type of stuff only happens to me, but If something like this has happened to you then feel free to post. I think it looks like im going to be going to the Junker tomorrow when they are open, have a great easter guys.

MillerPKA

Weird, I go to GSU.

Shirleyda4runner

U the black one I saw by Lowes one day?

Shirleyda4runner

(Black 4runner)

MillerPKA

yeah i've been to lowes a few times for the truck. i was actually there about an hour ago picking up paint for the two toning doors experiment i'm doing right now. i'm in between coats just killing time. you have pictures of your rig? where do you live?

Shirleyda4runner

Garden District, pics http://www.cardomain.com/ride/740119

While your out painting your doors sometime today, you think there's a chance you could take some sockets with you and try and get the size of those O2 sensor bolts?

Shirleyda4runner

I didnt know anyone else in school did the Yotatech thing.

MillerPKA

I saw your runner out the other night actually, taking a left onto lanier right next to eagle village. sweet looking rig bro. i don't have a socket set down here man sorry

Shirleyda4runner

Its cool, I'll see you round campus sometime Ill be lookin for ya now.

MillerPKA

what's your name, i'll facebook ya, two 4runner heads combined can do some sick stuff

Shirleyda4runner

Way to make me hijack my own thread though, seriously anyone else reading this... can you help me out.

Shirleyda4runner

I sent you a PM with the name, I dont know if i can trust people on here... wait what am I sayin, I trust them more than I trust most other people... Jorge Duran-Colindres.

MillerPKA

this is a good group of people. i don't know what all they could do with a name either. check 4runners.org or similar for writeups on o2 sensor cleaning, maybe somewhere in the text it tells you what is needed to loosen it

Shirleyda4runner

Its not that its on too tight, its that it is not on at all, basically I put it back where its sposed to be but its just sittin there as opposed to being bolted on.

Shirleyda4runner

perfect 12 mm bolts, thanks man. If only I knew what thread they were and I would be on my way to lowes as we speak.

20005spd

you have encountered a common problem on the 3.4l exhaust system. there is 2 studs coming out of the exhaust for the 02 sensor(s) the nuts are the issue, they rot away untill there is no more nut then out it comes. in fact i have been keeping an eye on mine for awhile because they are almost completely rotted away.
what to do?
in my case since i am catching it before it happens i can heat up the nuts carefully, not to damage the 02 and use a chisel to break off the nuts. shouldnt be to hard since there is barley any nut there. then i will go to toyota to get the nuts & gasket. why you would go to a junkyard is a mystery to me, you will only find rusted nuts and old useless gaskets, lowes might have the nuts but you wont find the gasket anywhere but toyota, so buy it all there. then i will use a die set to clean the threads and install the 02 again.
in your case you must make sure the 02 sensor wires did not rub the exhaust and melt, they will need be replaced.
then you must use a die set to clean the threads on the studs, then using the nuts and gaskets from toyota install the 02 sensor(s)
i have california emmisions so i have 2 02 sensors, if you have 2 but the other did not pop out yet then do them both at the same time.

hope this helps you

Beartracker

Do yourself a favor and replace both sensors. That should have been done at 70,000 miles anyway. When you order the sensor keep in mind that the gasket does not come with it so you will need to order that too. Get you new nuts and boltz and your all set for another 70,000-100,000. They are not cheap by any means but you will see a big savings in fuel and the way it runs! Mike

PS Happy Easter!

NDMORETIME

I got a new O2 sensor from the dealer for $118 out the door. It came with the everything you need except for replacement nuts. I would just get a new one like stated above. My gas mileage has gone up by almost 3 miles to the gallon.

Beartracker

The price of the 02 depends on the engine and year. I've seen them as cheap as $85.00 and as high as $170.00. Please believe me when I say to make sure you ask them if they come with the gasket. Mine was not included and several others have stated the same when they got the box. Then they had to wait a few more days for the gasket. It sounds like you have a good place to deal with, most try there best to screw you,Lol. Mike

MTL_4runner

Not sure which O2 sensor fell out but likely it was the front. In any case you should obviously get a new O2 sensor gasket and 2 sensor mount nuts at the dealer (they are cheap, no need to go to a big box store because you're probably going to have a heck of a time finding them anyway). You may find the CEL does not go out even after returning the sensor to it's rightful position. If so, replace that sensor with a new one from the dealer.