Dukenukemx

Bunch of lights came on the other day and got the code for P0430. I cleared them and hasn't come back since but I know that won't last. I wondering if this means the O2 sensor is going or the Catalytic converter is going? O2 not big deal to change but if bank 2 is the rear of the engine, that catalytic converter is going to be a pain to change. BTW car has 172k miles.

pauloil

how is the car running and has the fuel efficiency dropped?

Oro

We got this code this fall when she took the car on a road trip to Oregon and got a bad tank of gas; the car ran rough on it and then constantly threw the code. Toyotas will throw this code when cat efficiency is below like 95% of design. This is a WAY higher threshold than other cars or needed for emissions. Very frustrating.

My suggestion is do nothing unless it comes back. if it does, put spacers on the (spark plug non-foulers) upstream side and be done with it.

http://www.amazon.com/Dorman-42009-S.../dp/B000CO91FY

You need to drill out the ends of these, instructions widely available. This will not violate emissions output levels but will calm the insane Toyota OBDII trigger.

hypervish

It could be the 02 sensor, my RX300 threw this code once and replacing the sensor after the CAT did the trick. It's also one of the cheaper 02 sensors, well under $100 on the RX.

Oro

I forgot to mention, there is a very simple way to test O2 sensors before just changing one on a suspicion. Put them in a vice, but a meter set to DC mV on the power wire and other lead to ground. When heated with a torch to cherry, you will see the voltage fluctuate rapidly between .1 and 1V ~ ish. You can google the proceedure to check my memory; I haven't done one in a while.

Dukenukemx

I think it has. I'm getting less than 20 MPG lately. The code still hasn't come back but what triggered it is what worries me. It does have 175k miles so I'm tempted to change the O2 sensor, but it could be a waste of money. A DENSO downstream Rear O2 sensor is only $50 from Rockauto, so it's not so bad but I doubt that was the cause.

I could just use a laser thermometer I have to test the cat.

BTW Oro this is the video I think you're talking about.

Dukenukemx

I measured the temp on the catalytic converters and got 300F before cat and 350F after. The O2 sensor was 450F after cat. Hard to measure temperature cause the cat sits right on the exhaust manifold which reads over 500F. The front is also 300F before cat and 350 after cat.