Engine warning light on in 02 Toyota Yaris

ivorystraws

Hi,

There's an engine warning light on in our Toyota Yaris and I've spoken to various different mechanics who all say different things such as...

• It's a broken O2 sensor which would cost 275 to fit a new one (Mechanic in Beaumont)
• They would have to do run some diagnostics first to confirm what's at faults and that would cost30 euro (Garage in Swords)
• A broken O2 sensor is a common problem for that make and model and it's not dangerous but it means that the car is typically using twice as much fuel!? (Garage in Artane)

What's the best thing to do here and if it is an O2 sensor issue, what are the typical costs associated with repairing such a problem? Any recommendations?

Thanks in advance.

Pov06

My 99 Yaris has the same issue.

Never had any issues with passing NCT so I presume it's not the catalytic converter and the O2 sensor like your mechanic suggests.

Fuel consumption for me is good. I get about 5l / 100km.

ivorystraws

Pov06 wrote: »

My 99 Yaris has the same issue.

Never had any issues with passing NCT so I presume it's not the catalytic converter and the O2 sensor like your mechanic suggests.

Fuel consumption for me is good. I get about 5l / 100km.

I never knew it was such a common problem with the Toyota Yaris. It passed the NCT earlier this year but the engine warning light has only started going on this past week.

Just wondering what the best recommendation s are on how to resolve this issue and approximately how much I should expect it to cost?

Max Moment

Only way to know for sure is to get a diagnostic scan done.

Max Moment

Only way to know for sure is to get a diagnostic scan done.

Atlantic Dawn

The sensors don't last forever and eventually need replacing. There's 2 types you can buy, cheapest is one where you splice the cabling from the new sensor in to the fittings on the old, more expensive and best is to buy one specific to the car where the fitting is the same as the original, there's a risk with the cheaper ones that the engine light may not reset. I would be thinking for a Denso sensor which is what is in the car from new would be around €100-€120 for the part and then depending how easy it is to get the old one out another €100 to fit.

Here's the basics, it's not a big job but unlikely something you would tackle yourself...

https://www.youtube.com/watch?v=LFR8Numjy7M

ivorystraws

Max Moment wrote: »

Only way to know for sure is to get a diagnostic scan done.

I understand that I can plug in a hand held diagnostic into the ECU and that sometimes the fault will clear and sometimes it won't. If it doesn't, it's a sensor issue somewhere, either dirty or faulty. In either case, the fault will have to be cleared after replacing/cleaning the sensor.
I could run the diagnostic for free and take a chance that it clears but I obviously don't have such a hand held device. From what I've read and been told by others who've done it, a diagnostic is a 30 second job.

The problem is I definitely don't trust at least two of the mechanics who've already quoted and basically talked crap revealing obvious lies in their statements. One of the mechanics seemed to be knowledgeable enough though.

ivorystraws

Atlantic Dawn wrote: »

The sensors don't last forever and eventually need replacing. There's 2 types you can buy, cheapest is one where you splice the cabling from the new sensor in to the fittings on the old, more expensive and best is to buy one specific to the car where the fitting is the same as the original, there's a risk with the cheaper ones that the engine light may not reset. I would be thinking for a Denso sensor which is what is in the car from new would be around €100-€120 for the part and then depending how easy it is to get the old one out another €100 to fit.

Here's the basics, it's not a big job but unlikely something you would tackle yourself...

https://www.youtube.com/watch?v=LFR8Numjy7M

Excellent response and thanks for the video! I probably wouldn't risk doing that myself and even buying the sensors on eBay aren't that cheap. You're in the ballpark of what's been quoted from a motor factors though but I just didn't think it would cost €100 to fit. I guess it depends on the mechanic/garage.

Thanks for the helpful information though!

ivorystraws

Pov06 wrote: »

My 99 Yaris has the same issue.

Never had any issues with passing NCT so I presume it's not the catalytic converter and the O2 sensor like your mechanic suggests.

Fuel consumption for me is good. I get about 5l / 100km.

Did your Yaris pass the NCT with that warning light on? Do you still drive around with it on?

Mech1

Dont ever believe that the "real life" job is as simple as the video!

I have a few special tools for that job and still it can be a ********.

Pov06

ivorystraws wrote: »

Did your Yaris pass the NCT with that warning light on? Do you still drive around with it on?

Yes, and yes.

I've a code reader, I can clear the code but eventually the light goes on again.

joujoujou

OP, just get it scanned. Code(s) will likely tell you what's wrong - no guessing's necessary. :P

Avns1s

Mech1 wrote: »

Dont ever believe that the "real life" job is as simple as the video!

I have a few special tools for that job and still it can be a ********.

What special tools are required?? I've changed numerous of these and all that's required is the correct spanner and perhaps a screwdriver to unclip the connection. And they have all been pretty much as simple as the video!

BTW Toyotas don't like spurious O2 sensors OP. You might be better spending more in the Toyota garage and getting the right part (once your sure that its the O2 sensor of course) than paying half as much in the motor factor and still having to get the correct Toyota part.

Pov06

Avns1s wrote: »

What special tools are required?? I've changed numerous of these and all that's required is the correct spanner and perhaps a screwdriver to unclip the connection. And they have all been pretty much as simple as the video!

BTW Toyotas don't like spurious O2 sensors OP. You might be better spending more in the Toyota garage and getting the right part (once your sure that its the O2 sensor of course) than paying half as much in the motor factor and still having to get the correct Toyota part.

Is it the pre-cat or post-cat one that is usually replaced in this case?

I have a P0420, not sure about the OP

JohnBoy26

Avns1s wrote: »

What special tools are required?? I've changed numerous of these and all that's required is the correct spanner and perhaps a screwdriver to unclip the connection. And they have all been pretty much as simple as the video!

BTW Toyotas don't like spurious O2 sensors OP. You might be better spending more in the Toyota garage and getting the right part (once your sure that its the O2 sensor of course) than paying half as much in the motor factor and still having to get the correct Toyota part.

The threads can easily be damage when removing the old sensor so sometimes it does take just a little bit more than just a spanner.

Toyotafanboi

our 2000 yaris gave a check engine light the other year. it had a fault code stored for the oxygen sensor ut the car was running ok.

i took out the old one and cleaned it. made absolutely no difference whatsoever and the light stayed on. the sensor really is a doddle to remove on the yaris, gave it a few minutes to soak in wd40 and it came out with just a 22mm (if i remember correctly) open ended spanner. there is a lot of space around it to get your hand in from above, but from below it's even easier again. 10 minutes for a professional, 30 minutes if you've never held a spanner before.

the car passed the NCT with the light on and the emissions were within spec. the odd time the car idles a little rough so clearly the car is not perfect.

that said, the check engine light has been on nearly 2 years and been through one (maybe 2, i'm not sure) NCT's and it's passed. it's also still achieving between 5 and 6 l/100 kms.

obviously this doesn't mean your car is ok for sure, but...

ivorystraws

Pov06 wrote: »

Yes, and yes.

I've a code reader, I can clear the code but eventually the light goes on again.

OK I get ya. At least you knew exactly what the problem was. How much was the code reader if you don't mind me asking?

ivorystraws

Mech1 wrote: »

Dont ever believe that the "real life" job is as simple as the video!

I have a few special tools for that job and still it can be a ********.

I've no intention of even attempting this myself although I would like to do the diagnostics at least

ivorystraws

joujoujou wrote: »

OP, just get it scanned. Code(s) will likely tell you what's wrong - no guessing's necessary. :P

Yea I know that, that's not the problem. It's just a matter of where and by who and how much that would cost.

ivorystraws

Avns1s wrote: »

What special tools are required?? I've changed numerous of these and all that's required is the correct spanner and perhaps a screwdriver to unclip the connection. And they have all been pretty much as simple as the video!

BTW Toyotas don't like spurious O2 sensors OP. You might be better spending more in the Toyota garage and getting the right part (once your sure that its the O2 sensor of course) than paying half as much in the motor factor and still having to get the correct Toyota part.

I have confirmed that it is the O2 sensor so I'll ensure to get the right part. Thanks.

ivorystraws

Toyotafanboi wrote: »

our 2000 yaris gave a check engine light the other year. it had a fault code stored for the oxygen sensor ut the car was running ok.

i took out the old one and cleaned it. made absolutely no difference whatsoever and the light stayed on. the sensor really is a doddle to remove on the yaris, gave it a few minutes to soak in wd40 and it came out with just a 22mm (if i remember correctly) open ended spanner. there is a lot of space around it to get your hand in from above, but from below it's even easier again. 10 minutes for a professional, 30 minutes if you've never held a spanner before.

the car passed the NCT with the light on and the emissions were within spec. the odd time the car idles a little rough so clearly the car is not perfect.

that said, the check engine light has been on nearly 2 years and been through one (maybe 2, i'm not sure) NCT's and it's passed. it's also still achieving between 5 and 6 l/100 kms.

obviously this doesn't mean your car is ok for sure, but...

Thanks for sharing your experience. It has been confirmed to be the O2 sensor and think I've been quoted 198 euro to replace the sensor with a new O2 sensor. According to the figures I've seen thrown around here on the forum, that amount seems normal for Dublin for this work.

joujoujou

ivorystraws wrote: »

Yea I know that, that's not the problem. It's just a matter of where and by who and how much that would cost.

Whereabouts are ya? If Nortwest of the country I'll scan it for free.

Pov06

ivorystraws wrote: »

OK I get ya. At least you knew exactly what the problem was. How much was the code reader if you don't mind me asking?

Around 10 dollars on AliExpress.com

Pov06

Toyotafanboi wrote: »

our 2000 yaris gave a check engine light the other year. it had a fault code stored for the oxygen sensor ut the car was running ok.

i took out the old one and cleaned it. made absolutely no difference whatsoever and the light stayed on. the sensor really is a doddle to remove on the yaris, gave it a few minutes to soak in wd40 and it came out with just a 22mm (if i remember correctly) open ended spanner. there is a lot of space around it to get your hand in from above, but from below it's even easier again. 10 minutes for a professional, 30 minutes if you've never held a spanner before.

the car passed the NCT with the light on and the emissions were within spec. the odd time the car idles a little rough so clearly the car is not perfect.

that said, the check engine light has been on nearly 2 years and been through one (maybe 2, i'm not sure) NCT's and it's passed. it's also still achieving between 5 and 6 l/100 kms.

obviously this doesn't mean your car is ok for sure, but...

The rough idle is normal for the yaris. I think once hot they should idle at 550 to 650 RPM.

ivorystraws

joujoujou wrote: »

Whereabouts are ya? If Nortwest of the country I'll scan it for free.

Thanks, that's vey kind to offer but I'm in North Dublin plus I've paid to have it scanned already now.

ivorystraws

Pov06 wrote: »

Around 10 dollars on AliExpress.com

Really? Wow, that's cheap and I've never even heard of AliExpress.com. Thanks.

Pov06

ivorystraws wrote: »

Really? Wow, that's cheap and I've never even heard of AliExpress.com. Thanks.

http://www.aliexpress.com/item/Universal-Mini-V1-5-ELM327-OBD2-Bluetooth-Auto-Scanner-OBDII-2-Car-ELM-327-Tester-Diagnostic/1578466645.html

These ones are the handiest as you can connect them to your phone and look at live data and codes on your phone.

When you buy this you'll also need an app called Torque for Android. It costs about 2 euro in the app store.

The advantage with the bluetooth scanners is that you can just keep it plugged in all the time and be able to look at it anytime with your phone.