'01 O2 sensor replaced not working still..

[travellingnewfie]

My '01 4Runner keeps having the check engine light and VSC Tracking System lights all come on at the same time. I have replaced one O2 sensor, the dealership reset the lights, now FOUR times, and the lights keep coming back on. They are telling me that the code for the O2 sensor is wrong, have driven the truck with the computer on and all my air/fuel numbers look fine. It's under warranty now, should I have them replace the other O2 sensors or maybe the A/F sensor??? Any suggestions for the very frustrated, esp. when the warranty is running out quickly??!!!!

[Brian R.]

What codes are you seeing in the ECM output?

http://www.automotiveforums.com/vbul...0&goto=1840630

[ToyotaTech]

p0171?

[toyotamdt]

it is not the o2 sensor the code is being set bay the MAF sensor it is on the engine side of the air box. remove it and look at it on side will be clean and the other side will be covered in oil vapors and pcv vapors