Back40

Anyone ever replace an O2 snesor on a Rav4? Ran over to Autozone to check the code (check engine light) and got a PO420 which is Catalyst System Efficiency below Threshold. The Autozone guy suggested an O2 Sesnor but he couldn't tell which one. There are 2 on the exhaust manifold. Then he looks it up the price and says $459.00 each! The other Autozone guy suggested I clean both sensors with brake cleaner. I plan on checking with my local Toyota parts dept Monday but just though I'd ask for feedback.

MTL_4runner

That sounds more like a catalytic converter than an O2 sensor.
If you need a new one, just get an aftermarket (an OEM is huge $$$$).

Toytech

You need get have the ECM reprogramed, there is a tsb on it. And I think OEM 02 sensor are only around $150, or $250 if it's an A/F sensor.

Funrunner

I threw a CEL on my Toy truck and it turned out to be a Code 21 (O2 Sensor). I had to have a mechanic check it since the auto parts store can only do 96 and newer vehicles. The total was $326.88. The sensor itself was $197.11.

If you can do the work yourself I highly recomend it. Good luck.

The truck is still running bad and has to go in again. ugh. More $

MTL_4runner

Just do a search and you'll get a good idea for what this code means:
I did the search and here is what I found

Pretty much what I said above.

Back40

Is there a link to the Toyota tsbs on this site? Thankis!