Topic: o2 sensors

[Jokeass-Wheelers]

i have a 1990 22re in my 1982 toyota and someone says that the smog calls for 2 o2 sensors there is one located on the exhaust but i didnt ge tthe rest of the stock exhaust so i have no clue where the other one is supposed to go or where it would be located i have the wiring for it but do not know where it needs to be located

[OOPS]

My 90 only has one.

[GONZO97]

same with my 91

[2manytoys]

My kid's 91 only has one also.

[yotaneck13]

there is only one should be right in front of cat.

[fade]

yup all my pre 95.5s about 5 of them only had 1 o2 before the cat

[Sparkplug]

some of them do have 2 o2s, depends on the truck i believe and year. I think it started in 92, and it may have only been for california

[junya92toy]

usually obd1 has one and obd2 has 2 or more

[CCM Runner]

mine has 1 before the cat and after the cat... maybe its a california thing

[junya92toy]

What OBD does your runner have?

[Jokeass-Wheelers [OP]]

well mine has the wiring for it but i do not know where i need to put it

[junya92toy]

One before and one after the cat

[Jokeass-Wheelers [OP]]

for far behing the cat does it have to be

[yotaneck13]

as far behind as the one is in front

[Bobby Hunter]

1 before the Cat = 49 State
1 before one after Cat = Cali

[Jokeass-Wheelers [OP]]

ya i live in cali thanks for the help guys

[iasithol]

A little follow up to this question....
I have an 81 PU, CA emissions.   It has an Oxygen sensor located in the header.   

I just saw that the wire from the sensor somehow got ripped out.  I can't tell where the wire should mate into a wiring harness from the sensor.  I've looked all over and haven't seen it.  The shop manual only has a schematic - not an actual physical location.

Can someone tell me where the wire from the Ox Sensor connects to? 

[jl93221]

I went through this a while ago calif. calls for 2 o2 sensors, 1 before the cat and 1 after, I also had to get the computer for that year then add the wires to hook up the other o2 sensor. I also had to add the the egr gas temp sensor and wire it to the computer if your going to a referee they wont let nothing get by

[iasithol]

I've been told that since mine is an 81 carberated, with CA emissions controls, the Oxygen sensor in the header doesn't do anything other than trip a CEL IF it senses the emissions are off.

So if the truck is properly tuned and running right, the Oxygen sensor won't really do anything.  If it's not properly tuned, it won't pass the SMOG check anyway.  So the sensor doesn't really do too much. 

So to solve my problem of not knowing where the wire to the sensor goes (still can't find it) I can just bury the wire in a harness somewhere, not hooked up, so that the smog tech won't see it. 

Then I'll pass  my visual and if the truck is properly tuned I'll also pass the emissions.

Does this make sense?  Anyone disagree?