Oxygen Sensors Warning Light - Ignore!

[Avensis Avenger]

Dear friends,

Since buying my car (Avensis 2005 petrol auto) I have run the gauntlet of warning lights owing to supposed oxygen sensor faults. A couple were replaced under warranty in 2008 and one out of my own pocket at expense in 2009. I then received another warning light and ignored it - it went away.

I now have another warning light with a code P0156: Bank 2 Sensor 2 fault. I am going to ignore this.

Question. Has anyone ever experienced an MOT (emissions) failure or engine damage from not addressing a warning light from an oxygen sensor?

When I asked the Toyota dealer this question years ago they said "it wont run right". It runs perfectly as far as I can see. This was the same Toyota dealer who said they had fitted a new oxygen sensor but had actually taken it out and put it back on it.

I am wondering whether super twitchy oxygen sensors are leading many people to have sensors replaced for no good reason.

Many Thanks

[cooper12000]

depending which sensor it is it will cause the engine to either over fuel or under fuel...from what u hve said im going to take a stab in the dark and guess its overfueling. if this is the case u wull get poor miles per gallon as it is using excess fuel also u will end up poisoning the cat. no idea how much a new cat is but im guessing many hundreds how much is a new oxygen sensor in comparison to that never mind the extra fuel and other damage.

im not a fan of just swapping sensors unless the sensor has been removed and checked and proven faulty. sometimes sensors r swapped with no idea what has caused the fault all runs fine for x number of miles then it goes again cos the origonal fault wasnt diagnosed.

as far as the mot goes... im not sure of the date but some time last year they changed the mot to include warning lamps and the mil light. if any r on its a fail never mind the poor emistions

in other words take it to a reputable garage and get them to at least test the sensor b4 replacing it and diagnose the fault(s) and get it fixed!!

coop

[Avensis Avenger]

Thank you for this advice, which I will follow. Would you or anyone else know how much it would cost to have it tested?

Thanks.

[Avensis Avenger]

PS Re: for the MOT, it is my understanding that an engine warning light would not be an MOT fail. See: http://www.dft.gov.uk/vosa/repository/CHANGES%20TO%20THE%20MOT%20TEST%20EFFECTIVE%20FROM%2020%20MARCH%202013.pdf

[Avensis Avenger]

Hi all,

I ignored the warning light and reset the code with my ODB checker two months ago. The error (P0156: Bank 2 Sensor 2 fault) did not resurface.

HOWEVER - I now have a different fault, two months on - this time its P0031 - Bank 1 Sensor 1 Heater Control Circuit Low. I have deleted the code thrice, but it keeps reappearing.

Should this not dissapear I will need to locate the sensor and have it tested. Toyota have quoted £340 odd for the work - no thanks.

Question - Has anyone recently sourced a new sensor? If so please can you tell me i) where, ii) how much it was and iii) how complex a job it was to replace the sensor?

Toyota should be replacing these for free. There is a design fault with wither the car or the sensors.

Many thanks

Avenger