Newbie - need help w/advice on O2 Sensor issue - truck is '00 Tundra SR5 Access Cab

Hi. I'm new here and I already did a search before posting this question. I found some good information but since I have photos of the problem I'll describe, I figured it might help me get a better answer from the group.

Problem is this: my check engine light came on about 3 weeks ago. What's funny was that the VERY same week (and this is no BS - true story), I had scheduled to get my truck inspected for emissions (I live in the Atlanta, GA metro area) later that week. Not even a day later, the good old check engine light is staring me in the face.

A little history before I go any further: I do know about the crappy O2 sensor issues that have plagued Toyota Trucks - and I aint happy about it! The front (in front of the cat. converter) 2 O2 sensors went sour about 2 years ago and luckily the local dealer here did the right thing and replaced them at no cost. The back 2 sensors went out about 6 months ago and I bought some cheapo O2 sensors from a mail order internet site. I installed them fine and werre working just fine up until 3 weeks ago.

I checked w/Auto Zone (just to be sure) about the codes for the check engine light. They hooked up the reader and it read that the 2 back sensors were bad. As you can see from the photos, they really don't look that bad (I took the left side off and it almost looks new). Anyway, while taking the last nut off the 'stud' on the right side, the nut somehow got cross-threaded going BACKWARDS off the stud. By the way, I assume that is what the part is called - the stud (the threaded part that is welded to the truck). II went ahead and ordered two new sensors for the back - but it looks like I'm going to have a hard time installing them without a secure seal, correct?

Please check out the pictures (link below) and advise me on what route I need to take to get this resolved. I assume this part will have to be bought from Toyota or a junk yard and the re-welded? Here I was, thinking this would be a fairly easy fix (and I learned my lesson about buying crappy O2 sensors). FYI, I endup buying Bosch O2 sensors. I still can't believe how &*&%! expensive these are. My truck is almost 8 years old for gosh sakes! Nearly $220 for 2 little sensors!

Anyway, check out these photos and email me or post here what you think I need to do next (and don't say trade in my truck for an '08! - I still love my old '00 - and no payments!). Thanks in advance for your answers!

Pics:

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Reply to
jmdubya
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First, let me compliment you on great pics of the situation!! Sure makes things easier to see. Won't question how it got that way, cause it really doesn't matter. My suggestion is to get a tool known as a "nut splitter". This tool is inexpensive #1, and will allow you ( if space allows) to get the old nut off. From the pics, looks as tho there is enough room. Once the nut is off. my recommendation is to purchase another "inexpensive tool". aka as thread chaser. This should allow you to repair the damaged threads and press on with O2 sensor. Try this before spending big bucks for a shop fix :>)

Reply to
Bill Hall

This is pretty common on this truck, man. It's a dumb design. I'd bet that the issue isn't cross threading but seizing because of oxidation instead. The good news is if you didn't try to wrench the nut too far off the stud, the threads still might be alright. 9 times out of 10 a few seconds of exposure to a torch until the nut starts to glow will do it. I always kept a mapp gas mini torch in my box, and if that didn't work I'd wheel over the oxi acytelene to get it nice and hot (just be careful not to blast the whole stud itself off - the oxi gets REALLY hot). While it's still cooking, put a wrench on it and work the nut back and forth, and the oxidation should break away leaving threads that are still useable. Home Depot or the like sells small mapp and oxi acetylene tanks for like 30 bucks or so. And when you go to put the new sensor on, slop some anti seize on those threads, save you some headache in the future.

Reply to
qslim

===== ===== For the OP.....

What he said, ditto....your best advice for getting them off and salvaging a nightmare situation.

anywhooo.... as does Q.....I keep the mini torch in my box and when it fails...drag over the acetylene set.

again...for the OP.....

FYI, this situation happens on nearly EVERY toyota exhaust flange nut....the reason is dissimilar metals in contact with each other. (or the main reason) Basic recipe for a battery or electron transferance, which inturn, in either case, causes the two to stick togeather. (and let's not discount the rust thing either)

put it in a bowl....mix it up ...adda dash of.. "mite uh been overtightened"...and you cook up a fine batch of "fk'd up design". (fact, not fiction)

anywhooo....... having HAD to take several hundred of these same bolts off over the last 18 years doin transmissions... my experienced suggestion would be that......

The oxy/acetylene usage is virtually paramount when removing ANY of these Yota flange nuts that have any age to them.

I've always had the luxury of have'n the acetylene.... you maybe able to try the "soak it and work it" method of using penetrant and working the nut back and forth....don't know...don't have the patients for the method, and quite frankly..the torch works great.

As a last note......WHEN...these things strip on you......

:)

the EASIEST thing to fix it..and the cheapest..??..... is to burn out the old studs and use nuts and bolts. (fact,not fiction)

The ONLY other logical decision to made..??.....would be to take the pipes off and use a machine shop. (fact, not fiction)

Not what you wanted to here....i'm sure..but...... there it is dude......and keep this in mind.. EVEN...experienced techs have this EXACT problem you're facing now, so don't go beatin yer head against a wall.

you broke it...... now....fix it!!!!

~:~ MarshMonster ~takes a toke......wonders if he shudda stopped at... ditto..what he said~ ~:~

Reply to
Marsh Monster

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