Are the front and rear O2 sensors interchangeable on the 3.4?
 

So when I was cleaning the rear O2, it busted in half when I took it off the tailpipe - its currently taped together and seems to be working fine -

But I do have an extra brand new denso O2 sensor for the front kicking around - so on to my question:

Can I change out my current used front O2 sensor (30K on it versus 103K for the taped together one) and replace the taped together rear one with it? Basically, are the front and rear O2 sensors on 3.4 liter tacomas interchangeable? I would then put the brand new O2 up front.

Thanks,:bigok:

They are the same.Unless you have a CALI model with a A/F ratio sensor.If so ;I don't know.If not ;they are the same PN!

Confused yet?

absolutely.

on the URD website they list different part numbers for front and rear...

1998-1995 V6-3.4 4WD; Front = 234-4161
1998-1995 V6-3.4 4WD; Rear = 234-4154

Why is the front sensor so expensive on URD? $171 on URD and $96 from trdparts4u.com? The rear sensor is cheaper on URD $83 compared to $96 on trdparts4u.com

Any reason why?

When I installed both of them the only difference was one of the wires were longer on one then the other.

The CA 4Runners and 01/02 years have an O2 sensor and a A/F sensor I believe.

Are you sure Toyota of Dallas gave you the right P/N? The $96 would be the typical cost on a regular O2 sensor from them, but not an A/F sensor. Gadget usually beats them by a few bucks, but there's no way he'll be over $70!

The answer is that on your 97 Tacoma, the O2 sensor itself is the same (not so on 99+ Tacos), but the pigtail connectors are different (thus they get different part numbers). So you can use it for the time being, but you should eventually get the right one and change it out.

The correct sensor for your truck depends on if it is manual or auto:

1998-1995 V6-3.4 4WD Manual; Front = 234-4161
1998-1995 V6-3.4 4WD Manual; Rear = 234-4154

1998-1995 V6-3.4 Automatic; Front = 234-4162
1998-1995 V6-3.4 Automatic; Rear = 234-4154

Never mind, I didn't even think about it. I was putting in 2000 4Runner into trdparts4u, but they don't know I have a CA model. So the $96 is just the second O2 sensor for pre '01s/non CA models.

Jamie, what do you mean when you say the connectors are different? If thats the case how can I connect the front O2 one to the rear O2 harness? Further, if it can connect why do you suggest that I eventually get the right one? I have gathered from searching a bit that the Rear O2 really only tells the ECU that the cat is functioning and does not effect A/F mixtures and engine performance...so is it going to do much harm running the front O2 in the rear for any significant amount of time? Obviously I just dont want to spend another 80 dollars on another sensor if I dont really have to.

What I mean is the sensor itself is the same, the wires/pigtail, connectors may be different so you're going to have to look closely and see if what you have now will work or not. I know one of the sensors has a longer pigtail than the other (don't remember which offhand). I suggested getting the right one because I would if it were my truck, but I'm just anal about stuff like that.....if it works, then you'd be fine. My suggestion is always to try and get the right part so if it were my truck, I'd sell the one you have and take the money and order the correct one.

So what P/N do you have now? Denso 234-4161? Toyota P/N?
I am sure someone on here would pay to take it off your hands.

There are two basic types of sensors used on the 5vz. O2 sensors and air/fuel ratio sensors.

All the O2 sensors used on the 5vz are the same sensor. The differnce is the length of the harness. You can use the front O2 sensor in the rear position and the other way as long as the harness reaches the plug.

Starting in 1999 on some 4Runners and 2000 for the Tacomas, Toyota started using the newer air/fuel ratio sensors. These look just like O2 sensors with the only physical difference that you can see is there is a very slight difference in the plug. An air/fuel ratio sensor will not plug into an O2 sensor plug and the same goes in reverse. So, if you buy a cheap O2 sensor and it won't plug into the front harness plug, don't force it because you may really need the more expensive air/fuel ratio sensor. If you force it or shave the plug you could smoke the ECU, so don't.

When shopping for a new sensor, make sure you are shopping for the correct sensor so you don't end up buying an O2 sensor for your air/fuel ratio sensor truck.

Gadget

Is it ok to Clean the O2 sensor? If so how is the best way to clean to sensor??:think:

The o2 isn't "cleanable" as say a MAF is....it is a replacement part.

Thanks Tark, just wanted to check!:hillbill:

Ditto......problem is that the acutal sensing tip is hidden so it is nearly impossible to clean effectively.

To add to this now ancient post: Does anyone have experience with various brands of O2 sensor? Prices vary dramatically, and I know you usually get what you pay for but...

Get the Denso Oxygen Sensors. They are OEM. I personally wouldn't use any other brand unless I had to.

:safari: