crimedog

If it's japanese made, the upstream sensors are 234-9042. At least that's the number I was given.

Brave777

Thanks CrimeDog! Any idea on the downstreams?

Brave777

I should have been more diligent. Found it here: http://densoautoparts.com/find-my-pa...icle-selection

Brave777

Originally Posted by ctravis17

Hoping to help the next guy looking for this info:

I found the Denso cutomer service line Customer Service: 1-877-675-5463
Very helpful

2004 RX330
B1S1 = A/F sensor Upstream Right
B1S2 = O2 sensor Downstream Right (this is located below the Cat on the drivers side with the connector on the undercarriage appox. below driver's seat.) Denso part number 234-4509 (locally $130)

B2S1 = A/F sensor Upstream left
B2S2 = O2 sensor Downstream left

Denso Parts site
http://www.densoautoparts.com/find-m...icle-selection

Installation instructions from Denso
http://services.densoautoparts.com/r...or_BW_DPAM.pdf

HomeinMass

I replaced all (4) o2 sensors and my cel and vsc lights went off. That lasted about 250 miles. They popped back on so I went to Autozone. The codes were po172 and po175. So I cleaned my maf sensor and they went off. Now every once in a while they pop on. So I just ordered a maf sensor on Ebay for $12 when Autozone wanted $98. It should be here in a few days and hopefully this is it.

Brave777

Unless I'm missing something, I'm going to try to do this in my own methodical way. My error is only P0240 which is Bank 1.

So I'm thinking I should buy 1 each of B1S1 = A/F sensor Upstream Right and B1S2 = O2 sensor Downstream Right.

Then start with replacing one of them and see if the light goes off.

Am I approaching this correctly? If so, which one should I start with first? I'm thinking the downstream since the O2 extenders that usually fix this (that I didn't have room to install) are placed on the downstream ones.

lecturer

Please I've similar problem. I've tried every means to resolve it but could not.

The checheckengine light, VSC, and Trac off indicators came on and remain. The car is moving fine but I am bothered about the significance of the lights. I had the car scanned and got codes c1223 and c1246 suggesting malfunctioning ABS and Master cylinder pressure sensor respectively. I also cleared the codes but they returned almost immediately after putting on the ignition. I don't know what else to do. My mechanic here is not helping matters too.

Please, i neeneedhelp seriously. I don't what exactly to do. I tried looking out for the master cylinder pressure sensor but don't even know where it's located in my 2004 lexus rx330.

Brave777

Just wanted to come back and complete the thread.

My issue is fixed now.

Here is what all I did:
I changed out all fluids for synthetics. Side note: Royal Purple in the transmission made a huge difference. I experience about 1/20th the amount of shudder as before.
Changed spark plugs
Cleaned MAF
Cleaned throttle body
Replaced PCV
Used Pro-Tec engine flush

Now I was down to the Cat or O2 sensors.

The fix for me was ordering 2 Denso sensors for Bank 1 and replacing both. Light immediately went away and hasn't come back on at all since their replacement.

holycowe

04 rx330 120k mi
CEL and VSC and TRAC OFF showed up couple days ago. Computer showed code (forgot#) evaporate small leak. Bought new gas cap from lexus around $50 and cleared the code.
so far so good

Quatro40

Does your suv makes a whiring noise from the tires when driven, if you wheel bearings are bad you would get those codes for the ABS.

stevestoy

I too have the P0420 code with the VCS lit up.
Thanks a lot to all who posted, give me great info on where to start, at the best cost too!