2010 IQ O2 SENSOR ISSUES

[AndyPuz]

Hi, first time poster, car novice, having issues with my 2010 IQ auto transmission.

Driving along the other week and the engine light came on along with the traction control light, plugged in code reader and it stated 'P0138 O2 Sensor Circuit High Voltage Bank 1 Sensor 2', have had the sensor changed at a garage, drove a couple of days and the light reappeared, back to garage where they gave it a service, again drove a couple of days and the lights reappeared.

The car appears to run fine apart from a drop in fuel economy.

Has anyone had a similar issue and if so is there a definitive fix as I absolutely hate long, drawn out, hard to diagnose issues.

Cheers, Andy.

[FROSTYBALLS]

Hello Andrew - welcome to Toyota Owners Club.

Topic moved to the IQ club.

[craggle]

As it says sensor 2 I'm guessing there are two sensors, probably one either side of the catalytic converter. Have to ask if the right one was changed?

Craig.

[AndyPuz]

I presume so, the garage checked their code reader and got the same code.

[Kuneha]

I could only assume there is a fault in the wiring/circuit.

[AndyPuz]

Would it be worth getting Toyota to do a diagnostic themselves (£65 a do) do you reckon? Are their code readers more likely to find an exact, definitive issue?

[Kuneha]

I would think the scanner that the garage used was/is good enough to identify what the car thinks is the problem. I would personally save the money unless you wish Toyota to carry out their own repair.

I would have the o2 sensor wire/connector checked. Perhaps they changed the wrong sensor as someone said earlier.

[dave hendy]

Did you fit a genuine sensor, this can make a difference? Wiring is the most likely but don't rule out the engine ECU!

[Mike46]

Hi Andy I was just wondering if and how your issue has been resolved? I have exactly the same fault on my 10 plate manual IQ had the sensor replaced twice (second at garages expense) serviced etc but lights still coming on in car and have checked with my obd reader p0138! Thanks

[AndyPuz]

Hi, yeah I took it to Toyota and they changed both sensors as the one I had fitted wasn't factory Toyota and they thought if they weren't the same brand they might not be compatible. Cost me about £360 but it's sorted now.

[Mike46]

Thanks for your quick reply Andy I will take mine to my local main dealer and fingers crossed it should be fixed. Thanks again for your reply