The car: '94 SC300 1jz-ge
The question: Where the heck is my third O2 sensor? I see the obvious ones in the manifold, but can't find the one in / behind the cat.
People are always talking about these 3rd and 4th sensors, but I'm starting to wonder if my car even has one.

Actually, there's one more question. When bypassing the EGR sensor w\ the resistor; Is it nessecary to remove all of the components, or will just bypassing the sensor do the trick?

The reason for these questions: My CEL is very random in that sometimes it's on, sometimes it's not. My car is very obviously running rich as I can smell it from the exhaust. I just learned today how to read the computer codes w\ a paperclip, but the CEL isn't on right now.

Thanks for any and all input!

 

If you have a 1JZ and not a 2JZ, then you might not have a 3rd. There is a reason that engine never came on the slow boat from Japan.

 

My bad.
Correction: 2JZ-GE

 

Come on people... It's a simple question.
Where there any years that didn't have the 3rd O2 sensor?
Any help is greatly appreciated.

 

There is no 3rd O2. You have one before the cat and one after. Your SC is a OBDI car. I may be wrong. It's been some time since my car was stock.

 

I own a 92 SC300 and I have only the 2 O2 sensors, OBD1.
Like DIrEctQL I have one before and after the CAT

 

i got only two. i have a 93 sc300 5spd. there isnt one built into the cat. i was under my car this past weekend thinking of removing that middle cat.

 

i have a 92 SC3 and i only have 2..and i can see both of them clearly just by opening the hood and looking down

 

Cool. Thanks all!
I only see two myself, but they're both on the exhaust manifold, none after the cat.
But, seeing as that's now cleared up, I really apreciate everybodies help!

 

Sorry to just jump in here and tell you all your wrong here, but i got a check engine light right now for Sub O2 Sensor in my 92 5 speed sc300. There is a 3ed o2 sensor under the car behind the catalytic converter. Its a 3 wire not a single wire sensor. Ill take a picture of it when i replace it tomorrow to show you where it is exactly.

 

i have a 93 sc300 5sp and i was under my car less then 24 hours ago. i dont have a third sensor. i have one in each exhaust header. there is the precat right after the cat and a second cat under the car followed by the two resonators and then two mufflers. there is no third 3rd o2.

 

The only sc's that have more than 2 02 sensors are the VVTI sc's (98+) and they have 4, 3 of which are on the manifold and i believe the 4th one is behind the 2nd cat.

 

California OBD1s came with a 3rd O2 sensor and I think an EGT sensor. The sane part the country had only two; one in each piece of the manifold.

I know I only had two, and I'm sure most of the people in here that say they had two, know they only had two because they worked on the car

 

Yep, I only had the two in the exhaust manifold.

 

Fixed my Check Engine Light, I was Slightly incorrect. The 3ed o2 sensor on my sc was a 4 wire, not a 3 wire. I also didn't take a picture of it but it looks the same as the other 2 without a plug, you have to cut the original wire harness. And it probable is just a Ca thing. The smog game is a lil different over here. I use to have a 240sx from Oregon that the first smog shop i took it to didn't like so much.