jwigley

Hey folks.

I am getting the P1135 code which relates to a bad oxygen sensor from what I can make out online.

It said:

Air/Fuel Ratio Sensor Heater Circuit Malfunction ( Bank 1 Sensor 1)


Any suggestions on replacement model and brand? Also, does this sensor exist in only one place in the engine compartment?

salimshah

stick with OEM sensors only. The range of goodness is very narrow.

Bank 1 is near the firewall.

Check out the sticky threads ,,, lot of good info in there.

Salim

artbuc

Denso aftermarket (First Time Fit) is equivalent to OEM, IMO. $94 from Amazon. Can also get OEM from Amazon for $158 or pay about $200 from on-line OEM supplier.

Access to Bank 1 is limited. My advice is to cut wires at sensor and use a 22mm deep socket. It will fit better than the standard 7/8. Forget about the special O2 sensor socket. I would spray the sensor threads with PB Blaster every day for a week or so before trying to remove it. Use the supplied anti-seize on the threads only and snug the new sensor down with a crescent or open end wrench. Be careful you do not over torque. It does not take much, similar to a spark plug. Disconnecting the electrical connector maybe the most difficult part of the job. I suggest you practice on Bank 2 to understand how you release the locking tab.

fastnoypi

stick with OEM or Denso. Do not be tempted by using a Bosch sensor replacement.

You can access the bank1 connector from the top if you temporarily remove the throttle body cable and bracket. It should give enough space to reach behind the intake manifold to reach the connector.

Or if your reach is long enough, you can follow the o2 sensor up to the harness from the bottom.

maxSteel

The connector is a pain. Opening it is easier if you spray it with contact cleaner. I was able to reach from both top and bottom.
I borrowed the sensor socket from advanceauto, I was happy with it.
I sprayed sensor base with PB blaster first, had no problems removing it.
Used anti-seize before install.

hypervish

If you have small hands, you can reach the connector from up top. It look less than 2 minutes for me to un-do the connector. You just need to shove your hand through the small gap between the intake manifold and the throttle body.

artbuc

I've had them pop right out and I've had them seized. Better to plan for the worst case. The special sockets flex and are usually 7/8. If your sensor is seized, the special socket will round off the sensor and you will be in big doo-doo. Do yourself a favor and use a 6 point deep 22mm socket. No reason to keep wiring harness intact when sensor is already toast.

salimshah

Art ..
There are more options:

I also have a deep offset box wrench set. The connector can pass through opening. Just perfect for RX.

One can prevent flaring of the special socket by putting a hose clamp around it.

And as you said, if the sensor is going to be tossed, one can clip it.

Salim

jwigley

Thanks guys, I appreciate the advice. I'll look for the sticky thread regarding this topic.



Real quick though, does this look like the right part?


I put in my car as 2001 Lexus RX300 and it says that this part is compatible. Looking for confirmation too though.

carguy07

You got it: https://www.clublexus.com/forums/rx-...el-sensor.html

jwigley

I always like to follow up on my threads.

I followed everyone's advice and sprayed the sensor with Blaster PB the night before I did the work.

I smooshed my hand through the top and could get my finger tips on the wire connector. I pushed down on the little clip piece and had my buddy pull it off from below.

Then my buddy had a closed ended 22mm wrench with elbow that we tried on the sensor side. The sensor popped free instantly without any real effort.

Then we put the new sensor in and cleared the computer codes. The dash engine light and VSC light went away and have not come back since. Looks like I'm doing good.

Thanks for the info.