Yeah. This should be easy compared to my '05 Subaru Legacy... that thing was terrible to get to.

 

So I replaced the bank one, back O2 sensor and i am still getting the PO37. Any ideas? I did use the cheaper Chinese O2 sensor, could that be it or something else? Not throwing any other codes. I did an oil change, cleaned the K&N filter, cleaned the battery terminals and the MAF sensor. Vehicle has 185,000 miles and has always run like a champ.

Thanks in advance

 

OK, so I have tried three O2 sensors for bank one, down stream O2 sensor, still throwing the PO37 code. Any ideas? Could this be remedied by changing the spark plugs? Something else? I cannot pass Colorado emissions until I get this fixed. Thanks in advance.

 

This solved my bank 1 sensor 2 issue on my 2004 RX330 - excellent write up, thank you!

 

great write up but just one question: did you clear the codes with techstream?If not, what are you using? thanks.

 

The best write up ever. Im a woman and it took me all of 15 mins to replace this part and clear out my codes!!! Thank you sooooooo much!!!

 

Greetings all!

When my '07 Rx350 hit 156k miles, the check engine and VSC lights turned on...

So i first tried resetting battery and re-tightening gas cap, both lights remained on...

Went to AutoZone to OBD2 it... Result: P0037 HO2S Heater Control Circuit Low (Bank 1, Sensor 2)

My plan is to DIY replace the Oxygen Sensor, however...

I've found that there are 2 types of Denso Downstream Oxygen Sensors...



I don't know which one to get. I've located my oxygen sensor, and it's location and parts are about the same as the given examples in this thread... (which lean towards the 234-4509)
But I also noticed that the Driver Side part is for Japan-built models... and I when I looked up my VIN#, results showed my vehicle was Japan-built... (so I'm thinking maybe the 234-4149 part)

Is there anyone that can help clear my confusion? Any comments and additional info is greatly appreciated! Thanks in advance.

 

Did not use techstream to clear code. just used an old Scangauge II OBD II code reader.

 

Does anyone have instructions on changing the upstream O2 sensor on bank 1? I know it is hidden behind the engine and is very difficult to get to. The downstream was a piece of cake following these instructions.

Thanks

 

I'm working on this right now as well. I was able to get teh sensor loose.
Actually pretty easy to reach, get under the car and have the right tools-pb blaster, 18" longs 3/8 swivel head ratchet wrench, and the o2 sensor socket.
The problem I am having is getting the connector loose. I can reach it from up top and hugging the motor. It requires removing some hoses and the throttle? housing.
I also have to grease up my forearms with vaseline and stand on a step ladder to reach it.

I can reach, press the clip, but it won't budge.
Pretty frustrated with something that should actually be easy as I can reach it.
If you are still working on this, be careful as there are a couple of things that can cut your fingers and I'm pretty sure the hood latch just dislocated a rib.
But that's my fault.

I read that some people suggest cutting and splicing the wires. But that seems an very hard reach.
I will let you know how I end up getting connector loose.

I did make sure that I could bust the o2 sensor loose at the fitting before messing with the electrical connector.

 

Okay,
A late update.
I got the sensor off. Pretty easy once I figured it out and had a plan.
You need a helper.
I got under the car, reached up and depressed the clip while the helper used a pair of long hose clamp pliers to grip the sensor connector.
Once I depressed the clip and told him okay, it took all of 5 seconds to come off.

I did have to take off the plastic intake manifold cover and loosen the throttle housing to get to the clip from above.

 

I'm going to replace the b2s1. Could you please post a picture showing where it is located? Thanks so much!

 

It is in front of the engine, but I can't remember if it is the top or bottom one. Both are easy to get to.

 

Hi Folks,

Very informative post, is the bank 1, sensor 2 position the same for an 05 RX400H please?

Thanks,
JJTJ17

 

Welcome to Club Lexus.