GoodRevs

In my two years of owning my 79k 2001 ES it has been rock solid reliable, no problems. However tonight both the CEL and Trac Off lights came on and stayed on even after multiple warm starts. Haven't pulled the codes yet, but any idea's? Two things of possible relevancy:

- Four days ago it was at the Lexus dealership for an oil change and tire rotation/balance/alignment.
- I got a phone call that stressed me out when I was chilling in a parking lot. I got pissed and kinda nailed the accelerator a few times, took a few sharp turns, braked hard on my way out. I didn't hit anything or jump a curb or anything like that, just drove it hard for a minute. I never drive like that, I baby my 01 ES (seriously). The lights came on shortly after that.

EDIT: Should've mentioned the car seems to drive fine, everything seems normal, but I haven't had the time to drive it much since the lights came on. Tomorrow I will. Also I saw the other threads on this issue, I'll check the gas cap.

GoodRevs

Only one code was present, 1155.

mdbrown

That code is for the Bank 2 Sensor 1 O2 sensor heater circuit failure. Could be wiring, probably needs a sensor. A coincidence about the driving. If you had damaged or pulled the wiring you'd have more codes...

GoodRevs

Confirmed by Lexus that it is the Bank 2, Sensor 1 Heater Circuit that failed. Quoted over $450 to replace it which I held off on. Can anyone confirm where exactly this sensor is located? I found two; one near the radiator and the other down near the firewall. Also I have a part number (89465), is that the correct sensor for the one I need to replace?





EDIT: I'm confused on which bank it is, I'm seeing sources all over the place saying code 1155 is B1S1 and others saying B2S1. Which is it?

Amadauss

My guess is closer to firewall but not sure. I would do the change yourself. Not that hard to do and if it is the firewall, there is a thread on the site with pics showing a tool you can buy cheap which is designed to help change it, I think in the RX forums which is similar. the sensor is 75 dollars on line.

Just checked, its the first sensor before the Cat. That one is even easier to change.

GoodRevs

Yes, very confusing because there is some incorrect and unintentionally wrong info out there, but I THINK that bank 2, sensor 1 is the front one that should be much easier to change. I'm not sure if all the different part numbered sensors are the same but I think they are, only difference being the length of the cable. Can anyone provide a specific part number beyond what I listed?

GoodRevs

All done. For future reference: Denso part number 234-9021 is the OEM sensor and replaces the Bank 2, Sensor 1 (first) A/F sensor when code 1155 is triggered. Amazon has the best price I could find. Time involved is like 5 minutes, couldn't be easier.