I got quoted like 420.00 to replace the O2 Sensor on my car. I know I've found them a ton cheaper online, like 170 for the Denso.

My question is this: Is the following referring to pre-cat front or pre-cat back?

This is the codes I have.

P0125 Insufficient Temp for closed loop
P1133 O2S B1S1 Circuit Response Fault
P1135 O2S B1S1 Heater Circuit Open/ Or Short


Thanks so much in advance!!!

First I would recomend beginning at the first code. The engine will not go into closed loop if it is not getting to the correct temp ( around 180 deg f). First, replace the thermostat, make sure it is 190 deg, it could also be the temp sensor. Keep in mind that the temp sensor for the computer is not the same as the sensor for your inst pannel.
As far as the O2 sensors, I purchase mine off ebay, I prefer bosch, although there are several other good brands. If you buy the universal bosch you can get them for less than $40 each, I replace all at the same time. With the universal sensors, you will have to re-use the old connectors. I recomend soldering the connectors, and using heat shrink tubing.

Is replacing the thermostat difficult, meaning is it something I could do myself? I don't know where its located, I'm a car noob, but I have some friends that could help.

Hi ,
Please let me know where the bank1 sensor 1 location for Air /Fuel sensor is. I have a 1999 ES300 and get a P1135 . i see manuals of 1997 model showing it in the front near the radiator. Some say its near the firewall.
please advise.

Replacing the thermostat is easy, just make pay close attention which direction the old one is facing. On most cars it is possible to put it in upside down, which will cause it to overheat.

Don't have an answer unfortunately. Still haven't received the answer on whether or not that is precat front or precat back.

Follow your manual, on later models bank one is near the radiator. I have a 92, bank 1 is near the firewall on these years. I don't know why toyota decided to confuse everyone. Sensor one is pre-cat

Bank 1 is the bank of cylinders closest to the firewall (rear).
Sensor 1 is the AF sensor that is between the exhaust manifold and the catalyitic converter. This is the hardest one of all to get at.

If you face the V6 head on, meaning you would be standing on the passengers side of the vehicle at the front tire, and looking across the hood.
The bank of three cylinders that is on your left if bank 1 (rear), the bank of cylinders on your right is bank 2(front).

These OEM sensors go for about $225 from a Toyota dealership, a little more from a lexus dealership and less than $200 online. The stealership is going to charge you for a minimum of an hour's labor but it actually only takes about 10 minutes to swap the sensors out. The hardest part is reaching the connector.

You can easily do the replacement if you have a socket wrench and the proper O2 sensor socket.

steviej

Thanks much Steve for your responce. i just bought a sensor that has part number 89467-41030 froma junkyard es300 (not sure of the model , but the guy says its 2000) . But when i look at my car sensor part number,
it shows 894674-48011 on both rear firewall and front sensors.

can you please advise me if junk yard part 89467-41030 will work on my 1999 model .He did pull the part from the rear firewall location on that salvaged car.

apprecaite it.

894674-48011 is not a valid part number.

However, 89467-48011 is the part number for an Air Fuel sensor 1999-01. It is listed for the RX300. 89467-41030 is the same location sensor but listed for the same year ES300. It shouldn't matter because it is the same powerplant. Hopefully the wiring lengths are the same. From the sites I looked at, it will probably work. Just make sure when you get the new sensor, the wiring length is the same. Hopefully he didn't pull the O2 sensor instead. Air Fuel sensor is before the cat, O2 sensors are usually past the cat.

One way to find out. Match it to the bad one. If it looks the same, hook it up and see if your CEL goes out.

steviej

Thanks Steviej,

Actually that part that he pulled from that salvaged car doesnt match. Its shorter than the one i have. My car sensor part number is 89467-48011 and the one he gave me was 89467-41030 . Infact his sensor has a differnt connector on the end . The pins are flat and doesnt go in to the electrial connector. Both of mine front and back match. Do you think he might have pulled the wrong part/o2 sensor..? So now that it doestnt fit i need to get a another one.
Do you think that car will have the A/F sensor located somewhere else or does it go to the same location. He said he pulled it out from the rear.

If he doesnt have it, do you know any dealer i can buy it cheaper from for the same part 89467-48011.

thanks Again!

The one i got from salvage looks exactly like this below .. the end connector

http://cgi.ebay.com/ebaymotors/Toyot...mZ110301950879

the one i have in my car looks like this - the first picture below in the link here

http://images.google.com/imgres?imgu...%3Den%26sa%3DN

I hope u see are able to see the differnt there on the Flat pin end.
thanks

try www.oxygensensors.com for generic or www.parkplacelexus.com (~$175 ea.) or www.sewellpartsonline.com. Go to your local Toyota dealership with your AF sensor in hand. Play match-up there and see what they give you for a price.

I am guessing he pulled the O2 sensor. There is one on the rear bank but after the catalytic converter.

steviej

Thanks All for helping me out. I cant thank you enough.
I was able to replace B1S1 near the firewall on my 1999 es300 within 15 mnts. i did have the o2 sensor that i rented from Autozone. But i was able to use a regular 7/8 wrench to remove it . It was more easier for me and my hands were easily accessible to it. In my case it was a A/F ratio sensor and I bought it from ebay for 143$.
i had recd p1135, p0171 and p0172 enitially, after i took the old sensor out cleaned the end and put it back , i still continued to see the error code p1135and now p1133 and p0125.
once i replaced the sensor on b1s1 ,cleared the error codes, started the car, what a difference in the RPM. I always thought the RPM i had was a little higher than normal . before replacing the sensor It used to be at about 1500 -2000 when i start the car and idling, but would come down to 800-1000 when i change the gear. I had also noticed higher rpm at 2500 when driving at 50 speed.

After changing the sensor i noticed the RPM was at 1000 when i start and emmidiatly it came down within 500-1000 when idling.
Also i noticed i was now going at 60-65 at 2500 rpm. Hope these above observations are normal for this car. ?...
I havnt seen any codes yet. I do have a scanner and i was able to see all the emmision codes (CC, O, OH) finish scanning and no error codes yet after driving 30 miles at 50-65 mph. I still have the (EV) yet to finish its course. I hope that wont cause my emission to fail.
Since i have a emission test to be completed by tomorrow(failed once earlier) , i was told that any one of the 3 (cc,o, oh, EV) ? needs to cleared to pass the test.

Thanks again for all your help. Next is to see what is causing my car to leave one or 2 oil drops in my garage every 2-3 days.I hope you all will continue to help me learn more about my car and how to fix it.

Hi I have un connected the eletrical connector for b1s1 sensor, but have trouble to remove the nut, is counter clockwise to remove it? tried with different liq like deep creep, pb blaster, and even try to start the car for 10 min. still doenst work, any idea?

Thanks