P1153 code??? Need some help.
 

Board,

I have a 99 ES 300 with 191k miles. I recent have noticed that the car is running a little rough, but no lights. Today the CEL came on and had autozone scan it. The code was P1153. The tech said it was a pump located under the mass air flow sensor (sorry, but could not remember exactly what he called it), but I have replaced the mass air flow sensor and it is located under the intake below the mass air flow sensor. He did say it was a small pump.

The part was $250. I searched here and see that P1153 is an o2 sensor error, but I have replaced the o2 sensors about 30k miles ago, so I would hope it's not them. Any suggestions as to if he is right? I hate to replace that and find out that did not do it.

Any thoughts? I was thinking of removing the o2 sensors and put an ohm meter on it and see if I get a reading.
Thanks
Rusty

From here: http://www.troublecodes.net/Lexus/
P1153 is "Air/Fuel Ratio Sensor Circuit Response Malfunction (Bank 2 Sensor 1)"

Since there seems to be some confusion about what the problem really is, maybe you should take the car to a Lexus dealer's shop or some other shop you have confidence in.

update:

Removed the wiring connection on the forward 02 sensor and used the ohm meter. There was a reading, so I assume that sensor is working (assumption made from past, when replaced a 02 sensor that was bad and had no ohm reading).

May take to toyota and have them read the codes.
Still working on it.

The sensor may not be switching as fast as it was supposed to

Update: Just got ripped off at my local toyota. That's the last visit I will have with them.

Charged: $42 for tech to read code and "anaylze" it.
amazingly he got the same code that the autozone guy got for free. I guess "analyzing" was hard too, it took me 3 minutes to find what P1153 was online

Charged: $230 for 02 air/fuel sensor

Charged: $1 for hazardous waste??? - he read the computer, what waste, much less hazardous???
Charged: $2.57 for shop supplies???? - not sure what that was either, was that the paper he wrote on or maybe the lead in the pencil he used to write with??

They also wanted to charge $120 (1 hour) to put it in. Come on, it would take 5 minutes to replace the 02 sensor in front of the catalytic converter. No thanks, I've been ripped off enough today.

I ordered the part, so will wait and see if he was right.

Actually, you haven't gotten ripped off, since except for the 1 hour labor time (standard is 0.4) they wanted for putting a new sensor in, all the rest are typical dealer prices.
The lesson to be learned is: avoid dealerships if you can. After all, you and the majority of our fellow forum members are fairly well versed in mechanics.

Wow. Buying my own code reader was only $30 online, and finding out what a given code means online is free!

I know these are old posts but I just became a Lexus owner three weeks ago and other current and future members may still read these posts like I am. I saw that another member had used an OHM meter to test an O2 sensor. The O2 Sensor produces voltage and I've read on another post by "Eric the car guy" and he says that using an OHM meter can damage the sensor. A voltage meter should be used instead.

My first Lexus is a 1999 ES 300. She just needs some TLC.
So far, new tires, new struts and strut link bars, MAF sensor and soon a new O2 sensor (B1S2).