1991 Tojo 4x4 pickup...........Got my tranny done and now I'm installing a new cam, but in the meantime my son picked me up a new exhaust from the cat back. I was running with no muffler for the last 6 months or more. The problem is this: I have an o2 sensor just behind the CAT (also one in front of it)on the pipe and the new pipe he got me has no hole flange for the o2 sensor. What choices do I have? Can I just dangle the o2 sensor/eliminate it. Or drill a hole and try to mount it. I have no problem buying a new o2 sensor if I have to, but funds are starting to run a little low for this project and the boss is starting to question my every purchase now. I'd like to have it on the road by Sunday, but well see.

 

THis is for a Celica, but as long as the hole size is the same, it should be pretty easy to ad it to the exhaust you have now.

You have 2 O2 sensors because you truck has the CALI emissions. I dont know about getting rid of the second one.

http://www.carparts.com/details/Toyo...FS1p7Aod7mgAGA

 

That looks like it might work, but I wonder if it can be welded to a curved exhaust pipe or not.

 

Have a muffler shop fabricate a new one using and old exhaust pipe with the fitting or buy one. Should be cake for them (they do it all the time).

You cannot have the O2 sensor exposed to open air or your truck will run very poorly. It will sense all the O2 in the air and dramatically change your air/fuel ratio and even timing. I don't know if you can remove it completely either since that might also produce the same result.

If you buy a new one, buy a DENSO sensor. They work best, Bosch and other brands are known to cause issues or lower fuel economy.

 

Well, I just cut the old o2 sensor and mount off the tail pipe with my cutting torch. I've removed the tailpipe steel from the flange with a chisel and will then grind the edge, drill a hole in the new pipe and weld it on. Hopefully I didn't hurt the o2 sensor none when I cut it off. Why is it that some of the easiest jobs always turn out to be difficult?

 

Well, I tested the o2 sensor with my volt meter and it tested good so I welded it on and now ready to install. I feel better keeping it on since I have found that one thing is usually tied to another. Pull a link out and the chain falls apart.

 

I snapped one of the studs off on mine, bought one from BearRiver Converters: http://www.bearriverconverters.com/I...2-feda6aafd9f2

 

If this o2 sensor goes bad I'll have to do the same since I'll never get the nuts off this one. When I was younger I used to just love working on cars and trucks, but now it just seems like work and I keep forgetting where I put stuff and how it goes back together. If my old 91 weren't in such good shape I'd pawn it for something new. Of course old trucks and old men just naturally go together.

 

I'm still enjoying doing this in my 50's. I still do all my own work - it just takes more time - and I enjoy it.

 

I'm near 64 and one of the Ritis brothers pays me a visit just about all the time now. His name is Arthur Ritis and when he shows up I'm done working for a while. What a pest he can be sometimes. I just can't get to those hard to get bolts anymore and I don't have the strength in my arms like I used to even 5 yrs ago. I guess it's that downward spiral that everybody tries to avoid, but just can't. I still get the idea I can do things I used to when I was 30, but my body soon tells my brain to enter the rethinking mode fast. That's when I call my youngest son who is in his mid 30's and loves working on cars just like his old man used to. He's a Toyota guy too and loves my old truck probably more than I do. Come to think of it............that just might be why he gladly comes and helps me with it. He's probably just taking care of his future property in case I make that long, one-way trip. You know, the one where you can't take anything with you!
When I get it all back together I'm going to post a picture of the old girl so you can see what I'm talking about.
JohnW

 

Failing 02 sensors are more to due with carbon clogging the element than voltage issues FWIW. Definitely replace every 60k if not 30k. They make a huge difference in MPG, and aftermarket OEM equivalent Denso are only ~$50.