Oxygen Sensor Replacement

[Ryan B]

Hi all, my car (gen 7 140 ) has also fallen to this unfortunate problem which was confirmed at my recent service with MrT. At the time they cleared the sensor and the light went out but it came back the next day and like others I would prefer to fix this myself than pay the money MrT has asked for. But I don't know whether it was pre or post cat sensor. On the safety report the garage engireer reported "P0171 BANK 1 SENSOR 1 SUSPECT" so i ask does anyone know whether that means pre or post cat?

Having looked this up on the net others are saying its the air flow meter. Where is this located? The guy at MrT said it was the cat and would take 3 hours!

Ryan

[kenbarkeruk]

Dont clean your sensor with wd40 like he said ,it will only cost you for a new one in the short run, anything such as unburnt fuel,oil,coolant,wd40 etc,will effect how the sensor reads and decrease its life span.

[barrymmm]

I've just replaced the after cat sensor on my motor (bank 1 sensor 2 error) but the engine light stayed on. It wasn't a genuine Toyota part so I got a genuine one here for £34.99 - bargain! Light was still on so I sent it back for a replacement and tested it before installing it and it all checked out but I'm still getting the same error message. That's 3 different sensors and the same problem :(

I'm pretty certain the sensor is ok at this stage. Apparently, the it's reading that the heater in the sensor is either shorting or completely open circuit but I know that's not the case as I've checked the resistance across the sensor. Anyone got any ideas where I can start looking to sort this out or do I have to start tracing along the loom till I find the fault?

[cfc1]

I'll ask the obvious... did you reset the ECU (disconnect the battery) or use a code reader to turn the light off?

[barrymmm]

Yeah, I reset the ECU by pulling the fuses under the hood. This knocks the light off on the dashboard alright but it comes back on within around 10 seconds of starting up. From that point on it stays on :(

It must be noted that it doesn't seem to effect the performance of the car. It's not burning too rich or lean and all the power seems to be there. I'm hoping there's another connection somewhere along the wires that might be causing the problem because otherwise I can only think of replacing part of my loom or dealing with a fault in the ECU??? expensive and time consuming options...