O2 SENSOR heater circuit malfunction bank 1 sensor 2

[Bhellwig]

My Rav4 check engine light came on and I ran the code.. reported multiple O2 SENSOR heater circuit malfunction bank 1 sensor 2

So, I bought a replacement at my Toyota dealer for $250 bucks, popped it in and reset the check engine light ... life was good.

1 day later, check engine is back on the the same code is back ???

Did I replace the right one?? It's the driver side of the exhault manifold rigth in the front of the engine. 4 wire sensor.. sure seems like the right one..

I check everything again, I got 12v on the heater side of the plug.. reset and the drove it day and the light back on..

Any ideas?

[bondeoca]

Hello

If your error code is a 0141 then it is bank1 sensor 2 which is after the
converter.

Rick

[Bhellwig]

Thanks for the tip.. but I'm still confused.

When I think cat I think of the one way down stream in the exhuast pipe.. there is an O2 sensor way down there but it is of a different design..

In my manuals they refer to the bolbus pipe in the front of the engine between the manifold and the exhaust pipe as the cat.. They all so many models with sensors before and after this device..

My model appears to have only the an upstream?? 1998 California standard Rav4 has a f/a instead of the usual o2 ...

any other ideas???

wish I could post pictures

Brad [/img]

[Bhellwig]

Uploaded some pictures on my album...

[DJ Sueno]

From the error code you received, it appears that it would be the second O2 sensor... if you look at where the first sensor is, it is in the manifold... if you look straight down, you should see the second sensor in the catalytic converter housing... I don't have the exhaust manifold heatshield on, so you can see it better in my picture.... you can see it next to the transmission mount, the silver portion of the sensor sticking out of the catalytic converter housing... hope that helps...

[Bhellwig]

Thanks for the effort .. but mine is different.. from what I can tell it has just 2 O2 snsors one on the manifold the other under the car bolted like our pictuer after the cat..

Mine are both 4 wire heated sensors, I think because it's a California Standard system...

Thanks agian.. I think I am going to bite the bullet here and change out the other o2 sensor..

[2001SL2]

Hey, if the code you are getting is P0420, then its either the second 02 sensor after the catalytic converter, or it is the catalytic converter that is fried.

The other possibilities of why P0420 would pop up (might apply for manifold sensor too), include:
- Engine misfire
- Large vacuum leak
-engine oil leaking and going through the manifold.

If the connector of the sensor fit well with the one on the car then it is the right sensor, it might just be something else that is bad and not the sensor.

[Bhellwig]

Only the p0141 code..

[Bhellwig]

I got the after CAT O2 sensor on line at parts train about 120 bucks..

Put it in this morning and reset the check engine light... so far everything looks good..

Thanks for all the help.. The after O2 sensor on this Rav4 is under the passanger seat, pull out the jack and under the carpet is the connector... wire goes under carpet through the floor and out to the exhaust pipe..

:D :D

Just wanted to clarify something here.

I just replaced my "Bank 1, Sensor 2" O2 sensor on my 2001 RAV4 (2.0l). The part number is 89465-42090. We were getting the P0141 CEL (I have a ScanGaugeII to check...probably paid for itself with this fix).

The connector is on top, just to the right of the engine block as you're facing the car from the front. There is a brown color tag on the cable and two plastic anchor pins secured to the wire.

The wire drops down to the right of heat shield for the catalytic converter (again, as you're facing the car) and the sensor screws in on the bottom.

I used a 7/8" end wrench. I had to use some Liquid Wrench to free up the old sensor.

You need to remove/install the sensor with the wire free (not anchored or connected) as you will have to twist the wire as you're unscrewing the old/installing the new.