pluciorx

Hi
We have an RX300 2004 with 75000 miles on clock
The problem is that CEL + VSC lights are comming back with codes P0420 and P0430

Due to the below average mileage i'm quite not beleiving that the problem is the faulty CAT so i Plugged Mini-vci and trying to diagnose what is the cause

I'm attaching the graphs i took from the sensors today. Does that look about right ?

HtownBlue

You need to search for my post on this. It is extensive and will explain what your problem is. If your live data shows that the POST CAT O2 sensor is fairly consistent with its voltage reading, your cats are working fine usually.
Look for my post. It will solve your problem.

pluciorx

Thanks for answer i'm looking in to it now, will how do you read fuel levels ?

HtownBlue

You need a scanner thank you can tap into the system's cpu and access the LIVE DATA STREAM and look at the bank 1 and bank 2 O2Sensors which will be sensor 2 on each. This reading is the post cat converter reading. If it is consistent, the cats are good and you likely have vacuum leak or an injector issue.

pluciorx

so by the look of the screens i posted in first post do You think readings are consistent ?

HtownBlue

Without knowing if the throttle was being pressed, or having access to a longer time period of data, it on the surface appears to be bouncing too much for an ideal cat. That does not mean the cat is bad for certain, but could be a key indicator it is.

pluciorx

is there any chance you can do a scan on techstream and send me over the file so i can compare with mine ?

I took the reading just while seating in the car so nothing has been pressed etc. engine was just idling.

HtownBlue

Click this link. https://www.discountconverter.com/ca...rter-&News=120

pluciorx

I have managed to do more testing under the real conditions and it seems that the B1S2 is actually fluctuating slightly during acceleration, B2S2 looks much more constant (minimal fluctuations when accelerating )

In meantime changed the air filter, will drive some miles today to see how it works.

uh2

I just had a 0420 pop up earlier this week. I have an ODBC Bluetooth dongle...somewhere. I need to find it and fire up Torque.