Tahmeroo

My CEL came on with code P1135 (02 RX300). Most forum posts say its the a/f sensor. I've already read the DIY thread here. Amazon has the Denso part right now for under $100, which is $150 savings for the part alone at my local Toyota dealer (who said they would install it if I bought, but offered no warranty).

I'm ready to buy but want to be sure I'm buying the right item. Here's why: I found a thread on another site where someone said for this code if its a Cali emission car then its the a/f sensor and if it's not (I'm TX) then its an oxygen sensor. Confusing. However, the california emmission post was referencing a Highlander I think, and not the RX300 so that could be the diff?

Just making sure I'm buying the right thing.
Any advice is appreciated!

hypervish

The term a/f sensor and oxygen sensor is often mis-used. No need to worry, for p1135 you have to buy the Denso A/F Ratio Sensor, P/N 234-9009

lockie

I would suggest that you have your exhaust system checked out before you replace any sensors. These sensors are very sensitive and my experience has been that the check engine light is triggered when the sensor senses a problem in the system, not when the sensor itself is faulty. Even the smallest leak can trigger the sensor.

code58

That is true, but in this case I doubt it would be a false trigger because P1135 is specific to Lexus A/F ratio HEATER malfunction. It is HIGHLY unlikely that it would be anything but a broken heating element in the sensor. The car will run fine without replacing the sensor immediately and the only thing you would likely notice would be possibly a faint roughness for a VERY brief time when cold. It will not hurt anything running it till you get the new sensor and it's installed. Other elements of sensor failure may be of more concern, but this is not one of them. Been down that road and had to get a complete education in a very short period of time. If it were the front sensor, probably the mailman could replace it. Being the rear sensor, unless the OP is mechanically inclined, would be better if someone a little more experienced did the job, but Amazon is the place to buy it.

BTW, even though it shows the A/F sensor as Cal., my bet is that it will require the same sensor in all US states. I'm not personally aware they used Oxy. sensors up front anywhere in the US in the RX. You can look at the FRONT sensor (they're both the same) and check the part # that's lazer etched on it. It won't be the same # as the Denso # but is the SAME sensor. I believe it will be a 5 digit Toyota #, dash and then another 5 digit #. Should end in either 10 or 11 depending on whether it's original or has been replaced.

Tahmeroo

Thanks much for all the input! We are buying the part on amazon today.