1994 V6 OBDI O2 Sensors, Testing/Prices? - Toyota Nation Forum : Toyota Car and Truck Forums

Jeeves · 03-23-2006, 11:45 AM

So, last weekend I decided to do a tune up. Alright, My fuel economy is sucking, BADLY.
I did the plugs, looked like that hadn't been changed in the 120,000 the car had on it. Then I went to Autozone looking for O2 Sensors.

$66/apiece. $66 apiece.
Now, since my car is OBDI, I'm pretty sure it just has one per bank and not one after the cat too, correct?

Either way, $66 apiece is a bit steep to just go replacing both (3?) of them. So, how can I go about testing these before hand? I'm not sure when/if ever these were changed. On top of that is there a cheaper place to pick these up online? Thanks much for your help.

bronzemaxell · 03-23-2006, 01:45 PM

Quote:

Originally Posted by Jeeves

So, last weekend I decided to do a tune up. Alright, My fuel economy is sucking, BADLY.
I did the plugs, looked like that hadn't been changed in the 120,000 the car had on it. Then I went to Autozone looking for O2 Sensors.

$66/apiece. $66 apiece.
Now, since my car is OBDI, I'm pretty sure it just has one per bank and not one after the cat too, correct?

Either way, $66 apiece is a bit steep to just go replacing both (3?) of them. So, how can I go about testing these before hand? I'm not sure when/if ever these were changed. On top of that is there a cheaper place to pick these up online? Thanks much for your help.

94 v6 has OBDII brain, but probably only has OBDI connection interface.
$66 for o2 sensor from autozone is cheap, dealer OEM price is $125 to $150 each, but nomally you don't change it until the Check engine light is on, and telling you the O2 sensor is malfunction.

Cyorke · 03-23-2006, 03:06 PM

Jeeves, if you havent downloaded the repair manual taht is stickied at the top of the page try it. If you go to section eg2 and do a search for oxygen sensor it gives you specific tests to perform. It looks as if the tests are for the heater assembly in the O2 sensor though. THere are many pages that have the word oxygen sensor in it unfortunately so you may have to look for a bit to find what you are looking for.

also according to the manual there are 3 O2 sensors. the two obvious ones are at the exhaust manifolds then there is one after the cat. To remove it you ahve to disassemble the interior of the car to get it ou since the connector is under the carpet around where the center console is.

In the instructions it states that the tests need to be done within 90 seconds of disconnecting the battery so you may want to ahve someone help you with it if you can.

Like bronzemaxell said though if the sensors were bad you should get a MIL. Of course you can pull codes also to see fi there may be any stored inteh ECU. If so you could start with those.

Hope this helps.

Jeeves · 03-23-2006, 03:16 PM

From everything I've read, it didn't seem that the 1994 Model had OBDII at all. 1994 (IIRC) was the only year they used hydraulic cooling fan and so on. After 1994, there was a revision which led into the OBDII era.

Anyone else?

Cyorke · 03-23-2006, 03:28 PM

Just went to search it in the repair manual. Everything points to it being OBD II. Like bronzemaxell said it is OBD II but the connector under the dash is still OBD I. Unless the manual is somehow wrong, hopefully not though. The repair manual is for a 94 also. It says it is for 92-96 but it is the actual 94 manual. SInce most everything is the same between those years it works for most everything.

bronzemaxell · 03-23-2006, 03:29 PM

Quote:

Originally Posted by Jeeves

From everything I've read, it didn't seem that the 1994 Model had OBDII at all. 1994 (IIRC) was the only year they used hydraulic cooling fan and so on. After 1994, there was a revision which led into the OBDII era.

Anyone else?

i did a quick search on goodle

http://www.aa1car.com/library/us796obd.htm

1994 toyota camry, V6 ONLY, (1MZ-FE), has the early ODBII

Jeeves · 03-23-2006, 03:36 PM

Quote:

Originally Posted by bronzemaxell

i did a quick search on goodle

http://www.aa1car.com/library/us796obd.htm

1994 toyota camry, V6 ONLY, (1MZ-FE), has the early ODBII

Yes, and as stated by www.obdii.com/connector.html it's not fully OBDII compliant, while the 1995 was 100% OBDII compliant. There was a revision after 1994 in which the hyrdaulic fan was replaced, I'm wondering what else if anything was done to make the car OBDII Compliant. Digging through the official repair manual I host, I see reference to only two oxygen sensors, one on each bank. I don't see references in eg2.pdf to anything after the cat, where an o2 sensor would be required for OBDII.

Quote:

Originally Posted by Cyorke

Just went to search it in the repair manual. Everything points to it being OBD II. Like bronzemaxell said it is OBD II but the connector under the dash is still OBD I. Unless the manual is somehow wrong, hopefully not though. The repair manual is for a 94 also. It says it is for 92-96 but it is the actual 94 manual. SInce most everything is the same between those years it works for most everything.

What manual are you using?

Cyorke · 03-23-2006, 03:43 PM

the one that is stickied on the main Cmary page. It looks like you did the hosting or something like that. It says thanks to you for some reason.

http://www.toyotanation.com/forum/t62501.html

Cyorke · 03-23-2006, 03:50 PM

Quote:

I don't see references in eg2.pdf to anything after the cat, where an o2 sensor would be required for OBDII.

page eg2-307

Sub heated oxygen sensor

Jeeves · 03-23-2006, 03:54 PM

Quote:

Originally Posted by Cyorke

the one that is stickied on the main Cmary page. It looks like you did the hosting or something like that. It says thanks to you for some reason.

http://www.toyotanation.com/forum/t62501.html

I host it and I wrote the little TOC page. Nothing big.

Go figure that text is non-searchable. I'm gonna pull a connector and see if it throws a check engine light, something is not right. The engine has 130,000 and I'm getting beyond ridiculous gas mileage.

Cyorke · 03-23-2006, 03:55 PM

I jsut went and looked at my 94 V6 and there is definitely a third O2 sensor. It is located about a foot behind the cat before the resonator.

Jeeves · 03-23-2006, 03:58 PM

I do everything I can not to mess with my daily driver, that's what I've got the supra for.

However, you've pointed me towards what I need to know:

Quote:

2. INSPECT HEATER RESISTANCE OF SUB HEATED
OXYGEN SENSOR
(a) Remove the passenger’s seat.
(b) Take out the consol box side of the floor carpet.
(c) Disconnect the oxygen sensor connector.
(d) Using an ohmmeter, measure the resistance between
the terminals + B and HT.
Resistance:
11 – 16 at 20ºC (68ºF)
If the resistance is not as specified, replace the
sensor.
(e) Reconnect the oxygen sensor connector.
(f) Reinstall the floor carpet.
(g) Reinstall the passenger’s seat.

Cyorke · 03-23-2006, 03:59 PM

reading through everything just pulling it may not set the code. It looks like the problem has to occur twice
so if you pull it and no code then you may want to turn it off and try it again

I am using adobe to read it and have no problems searching

I can try copying the page or pages and pasting them here or search and give you page numbers so you can get to them easier
that book is a bitch to look through on the computer it is much easier when you ahve the actual book in fromt of you

Jeeves · 03-23-2006, 04:18 PM

Quote:

Originally Posted by Cyorke

reading through everything just pulling it may not set the code. It looks like the problem has to occur twice
so if you pull it and no code then you may want to turn it off and try it again

I am using adobe to read it and have no problems searching

I can try copying the page or pages and pasting them here or search and give you page numbers so you can get to them easier
that book is a bitch to look through on the computer it is much easier when you ahve the actual book in fromt of you

The text in the image no page 307 isn't searchable. That's what I was getting at.

If I pull all the o2 sensors it better give me some type of warning.