O2 Sensors Faulty - Common Problem

[Lizzi]

Hi all. Well I'm a month into owing my 2005 2.0ltr T3X, (39,000 miles) and have generally been happy with its performance. Got it to ferry family around - its a big car, (which I like) and the boots is huge!!

However, 2 weeks ago the Engine Management Light came on, and stayed on for the next couple of trips. Having no real idea on car engines (Apart from checking fluid levels etc!), I booked it back into the Toyota dealer I got it from. They cleared it, saying it had gone off due to the 2 oxygen sensors on the cat. (I do a number of short 4-8 miles journies, plus longer 30+, and 100+ mile ones. Two days ago, the light returned after doing a 4 mile trip, and leaving the car for about 30 mins. It was on the next day when I did a 20 mile journey, but off on the 20 mile trip home! I have phoned Toyota, who are going to change the O2 sensors on Tuesday.

I understand that this is quite a common fault? Could it be made worse by the number of short trips I have to do. (Have no alternative - take hubby to the station most days which is 4 miles away; cheaper to do it in my car than his 4.2ltr Jag...!!) However, am now worried that it could mean I've got other issues, that changing the sensors may not solve? Your opinions would be much appreciated.

Also, it was only after I'd paid for the car that I found this forum. (What a great place!) However, I'm now very nervous about this oil burning issue, that seems to hit after 40k miles, (which mine is now at). Does it effect the 2.0ltr 2005 models? Reading the forum there seems to be some that are this age and younger that have the problem. I've done around 800 miles since I got mine. Checked the oil the other morning when cold, and its smack bang on the max mark. Am I paranoid to worry about it?

Thanks in advance for anyone how replies.

[Gooli]

My car has got the same type of engine as yours, and has done 64,000 miles without any of the

oxygen sensors failing (there is four of them), so I guess they last just about as

long as on any other car. Like you, I mostly run short trips.

The 2.0 litre engines are not affected by the dreaded oil issue, as long as

oil and filters are changed at specified intervals.

[Allyjon]

My engine management light came on ( I have an 03 2ltr T Spirit). Turned out to be a faulty O2 sensor. Toyota quoted me around 250 quid to replace it. So I did it myself for under 100. A garage would probably not charge a lot more as it's a ten minute job. My avensis has done 88000 miles and does not use up any oil between services. I change mine every 6 months and the filter but that's just me being picky. Sensors are cheaper to replace than catalytic converters.

[bestseany]

My 2.0 vvti is on 89k and I had to replace an O2 sensor a few months ago, cost £140 from Toyota and I fitted it myself. It does seem to be a very common problem with these engines.

Although the 2.0 doesn't suffer the same type/degree of oil consumption as the 1.8 can (up to 1 litre every 1k miles after 40k miles), mine does consume a bit. Mine's currently burning about a litre every 4k miles.

[Lizzi]

Thanks for your replies. Luckily, I've had both mine changed under the warrenty. (I'd only had the car 2 weeks when the light first came on!)

Have had it back since Tuesday, and fingers crossed so far all is good.

I've done around 1,100 miles since I got the car a month ago. Have checked the oil a couple of times, and noticed that it is now about 3mm down from the max mark. Those miles included a couple of 200 mile motorway runs, so I suppose thats not too bad.

(Just to check - should you check the oil when the engine is warm or cold? - On my previous cars I've always done it first thing in the morning, when the engine is cold, and if ness. topped up when cold, but I see the manual says check when the engine is warm. Does it make a difference then??)

Thanks.

[Mackan100]

Hi there!

I don't think there's any problem by checking oil level with a cold engine in the morning, but if you crank it up idle, for just a few moment, turn it of, then it might look like you're low on oil. I don't know the circumstances about there you live, but in Sweden, all petrol have a 15% mix of ethanol.

Then i was working as a technician, after our government implied these petrol rules, we could clearly notice a frequent increase of "engine management light" related to oxygen sensor faulty values during hot days in the summer. Well both 1.8 vvt-i and 2.0 D>4 engine there affected, but it seemed like 2.0 there a bit more sensitive. Toyota just said that the engines complies to the mix, but we experienced another reality in the workshops. Our thesis there that the mixed in ethanol begun to boil just before injection during hot days then the engine compartment could be really hot. The result is faulty combustion, which leads to the next, and the next and so on...

But if you have an abnormal oil-consumption you will get a layer of soot/carbon on the sensors surface, that also leads to faulty sensor signals. But you don't seem to have that problem...

And some times they just, fails... thats it!

/Mackan100

former Toyota-Technician Toyota news & reviews

[bestseany]

I normally check the dipstick in the morning when the engine hasn't been run. I find that it takes a while for the oil to drop back down into the sump.

[youngalistair]

im worried about all the issues should i just walk away from buying one and find something else the one ive seen privately is a 1.8vvt avensis vermont estate 100.000 miles on the clock with F.S.H for £1200 am i just waiting to get into trouble the present owner has had it for just a year im thinking that hes also had so issues and maybe the sensors are staring to go off and showing o2 probs or am i just paranoid after reading peoples grievances

[Hasse]

Hi there!

I don't think there's any problem by checking oil level with a cold engine in the morning, but if you crank it up idle, for just a few moment, turn it of, then it might look like you're low on oil. I don't know the circumstances about there you live, but in Sweden, all petrol have a 15% mix of ethanol.

Then i was working as a technician, after our government implied these petrol rules, we could clearly notice a frequent increase of "engine management light" related to oxygen sensor faulty values during hot days in the summer. Well both 1.8 vvt-i and 2.0 D>4 engine there affected, but it seemed like 2.0 there a bit more sensitive. Toyota just said that the engines complies to the mix, but we experienced another reality in the workshops. Our thesis there that the mixed in ethanol begun to boil just before injection during hot days then the engine compartment could be really hot. The result is faulty combustion, which leads to the next, and the next and so on...

But if you have an abnormal oil-consumption you will get a layer of soot/carbon on the sensors surface, that also leads to faulty sensor signals. But you don't seem to have that problem...

And some times they just, fails... thats it!

/Mackan100

former Toyota-Technician Toyota news & reviews

Hi Mackan

It is nice to hear your explaination since I am living in Sweden too. And I got this problem the first day when we got a real warm weather. So what you wrote could very well be the reason behind problem I got.

My question is naturely what/how I can do to get rid of the problem. Would it help to clean the sensor, or must I buy a new one?

Thanks in advance.

[Lizzi]

Well having had two 02 sensors replaced a fortnight ago,(under warrenty), the EML has just come back on!

Phoned the Toyota garage that did the work, and their explanation is that there are 4 sensors, and often if one goes, the others follow, as it puts more pressure on the working ones? Does that sound correct to anyone out there?

They are putting through another warrenty claim to replace the other 2 now. (I'll throw all my toys out of the pram if its refused!)

That will mean the car has been back to the garage 3 times in the 5 weeks I've owned it. (1st to read the code/ clear it, 2nd to replace 2 O2 sensors, and now this.) - Not very impressed at the moment with the Toyota 'reliability'.

Do you think Toyota's explanation is correct? Whats the likelyhood of this having a knock on effect to something else?

Had an offer from Toyota to extend my 1 year warrenty to 2 years. I've just completed the paperwork, as I fear I may have got a lemon.

[t-spiritpete]

Well having had two 02 sensors replaced a fortnight ago,(under warrenty), the EML has just come back on!

Phoned the Toyota garage that did the work, and their explanation is that there are 4 sensors, and often if one goes, the others follow, as it puts more pressure on the working ones? Does that sound correct to anyone out there?

They are putting through another warrenty claim to replace the other 2 now. (I'll throw all my toys out of the pram if its refused!)

That will mean the car has been back to the garage 3 times in the 5 weeks I've owned it. (1st to read the code/ clear it, 2nd to replace 2 O2 sensors, and now this.) - Not very impressed at the moment with the Toyota 'reliability'.

Do you think Toyota's explanation is correct? Whats the likelyhood of this having a knock on effect to something else?

Had an offer from Toyota to extend my 1 year warrenty to 2 years. I've just completed the paperwork, as I fear I may have got a lemon.

Hi Lizzy, stick with it as once this is sorted then you should be fine, it's a bit a annoying to keep going back but at least they are paying and they can't refuse to sort it FOC during the warranty period, hot tip ..... just keep away from Supermarket fuel and drive the car with a bit of gusto now and then to keep the carbon away.

Good luck and regards .... Pete.