Engine Check Light Still Coming On!

[Toyota Mickey]

Can anyone help

My wife has a year 2000 1800 Avensis estate. Some time ago the engine warning light came on and after reading many threads about this I decided rightly or wrongly to change the 2 Lamda sensors on the exhaust manifold. I got 2 new ones from www.buypartsby.co.uk They told me that their four wire universal 86400 would be compatable and both sensors cost me £58. However after fitting them the car did not run correctly even after giving the ecu time to reset. This left me in the Sh*te :ffs: as I had used the link loom from the original lamdas to wire up the new ones and had cut one of the wires a bit close to the old units. Well £250 and 2 days later we had 2 brand new Mr T lambda sensors fitted and the car ran well but after a few miles the light popped on again. We then decided to take the car to the Toyota garage to get the faults read (quoted £46.00. And yes I know, thats what we should have done to start with :!Removed!: ) We were told that the 2 lambdas that I had changed were leaving a fault code ( this may have been the original problem or it may have been from when I fitted the universal sensors ) Anyway they cleared that fault and said it should be fine but" if it does come on again sir then it may be the CAT that is damaged" Well we drove off but the next day and about 30 miles later, guess what? the light came back on

I decided that I would remove the CAT and see if I could check the condition of it. Today I removed it and with the help of a 12v bulb on the end of a wire the CAT looks fine, well the rear of the core anyway. The Battery was disconnected for 1/2 hour so the fault light is now out. It is all back together and running fine.

Has anyone got any ideas as to what may be the problem if the light comes on again ( which I'm sure it will..........!Removed! thing :ffs: )

Mickey

[ulro]

Did you get the OBD2 error code from when the car was checked.

[Toyota Mickey]

Did you get the OBD2 error code from when the car was checked.

No, I should have done. I did not get charged for the check in the end so did not get an invoice. I will phone them up this week and see if they have record of it and also tell them the latest.

Mickey

[Toyota Mickey]

Did you get the OBD2 error code from when the car was checked.

The error codes were

P0171 and p1174

Aparantly the fault was the lamda sensor 1 on bank 2.

I am told that this one is in the exaust manifold so it has been replaced.

Hope you can confirm this?

Mickey

[ulro]

Just as I thought

The error code P0171 is generic and you can check the explanation of it here P0171

This code relates to a parameter that adjusts the fuel injection timing to compensate for wear and other changes in the engine over time. This compensation is normal but eventually this parameter value goes out of range and the ECU set the P0171 code and lights the MIL (check engine light on dash).

The other code mentioned P1174 confuse me. It is not a generic code so it may be a Toyota specific code but I doubt that. It could be that the tech. has read the code wrongly and it should be P0174 instead which is the same as P0171 but for cylinder bank 2. But this confuses me even more unless you have an Avensis with a V4, V6 or V8 engine. The straight four cylinder engine only has one bank.

Still I doubt the oxygen sensor but rather suspects the MAF (Mass Air Flow) sensor. This is common and what happens is that the sensor may get dirty over time and the sensor can not perform as intended. Therefore it is worth checking this and have the MAF cleaned. Inside the sensor there are wires of platinum that are heated with electrical current and over time deposit from the intake air tends to build up on the wires.

You can clean it yourself or have a garage do it for you. Of course you can also change the MAF but this is probably very expensive. Cleaning it only cost you a can of electronic cleaning spray and an hour spent doing the job. Do a google search on Cleaning MAF sensor. This link for instance is for Lexus with an excellent description and will be very similar to how to do it on your Avensis Link

Good Luck

[Toyota Mickey]

Thanks alot for the reply ulro

Theres a lot of useful information in your reply and in the links :)

So far the light has not come on again but at the weekend I will have another look at the car. I will clean the MAF sensor and have a good look round the vacuum pipes etc for leaks.

I was then thinking about getting my local garage to check the emissions from the exhaust to see if the car would pass its annual safety inspection as it will be due in a few months time. Will keep you posted

Cheers Mickey

[uumode]

Thanks alot for the reply ulro

Theres a lot of useful information in your reply and in the links :)

So far the light has not come on again but at the weekend I will have another look at the car. I will clean the MAF sensor and have a good look round the vacuum pipes etc for leaks.

I was then thinking about getting my local garage to check the emissions from the exhaust to see if the car would pass its annual safety inspection as it will be due in a few months time. Will keep you posted

Cheers Mickey

If it's any help in trying to pass the test, my old car had intermittent Engine Check light on - I reckoned it was the EGR (Exhaust Gas Return Valve) which passes some of the gas back into the engine again to burn up some of the nasties, which didn't appear to be connected to anything!) Anyhow putting in the cleaner premium fuel seemed to keep the light off, so in my case it was probably marginal and a cleaner fuel was a temporary solution.

[Toyota Mickey]

If it's any help in trying to pass the test, my old car had intermittent Engine Check light on - I reckoned it was the EGR (Exhaust Gas Return Valve) which passes some of the gas back into the engine again to burn up some of the nasties, which didn't appear to be connected to anything!) Anyhow putting in the cleaner premium fuel seemed to keep the light off, so in my case it was probably marginal and a cleaner fuel was a temporary solution.

Hello again,

I have been told that it may be related to the fuel we use????? We tend to fill up on super market fuel ( Im sure it all comes from the same depot tanks anyway! ) but have been using BP for the last few fills just incase it was that. The light has not come on again for a while so I hope it stays that way.

TodayI removed and cleaned the MAF sensor. It was quite dirty. Here is a pic of it when I removed it:

I cleaned it carefully with electronics cleaner and a cotton bud, didn't take a pic of it when it was clean but it looked like new!

I will see how we go!

Mickey

[xrec2]

Are you sure that is the maf sensor ? looks like the intake ambient air temperature sensor to me.

The maf sensor is down the "tube".

[Toyota Mickey]

Are you sure that is the maf sensor ? looks like the intake ambient air temperature sensor to me.

The maf sensor is down the "tube".

oh B*llocks ! Is it realy :ffs: Looks like I will be taking it out again this afternoon and having another look.

Cheers mate

Mickey

I have just re-read this link posted by ulro

http://www.lexusownersclub.co.uk/knowledge...p;id=50&c=9

Opppppppps

[uumode]

Hello again,

I have been told that it may be related to the fuel we use????? We tend to fill up on super market fuel ( Im sure it all comes from the same depot tanks anyway! ) but have been using BP for the last few fills just incase it was that. The light has not come on again for a while so I hope it stays that way.

Mickey

If the difference was borderline as in my case, a slightly dirtier fuel logically would push the emissions over the limit - providing the system was compromised somewhere - (obviously to a healthy system with all the emissions controls operative, it wouldn't make any difference).

http://www.bp.com/sectiongenericarticle.do...ntentId=7009013

"BP Ultimate Unleaded reduces emissions of unburnt hydrocarbons, carbon monoxide, nitrogen oxides, and carbon dioxide. The greatly enhanced cleaning power of the fuel removes carbonaceous deposits from the engine enabling it to work more efficiently which improves combustion, and in turn helps to reduce exhaust emissions."

Further reinforced by the fact I pulled into the petrol with the Engine Check light on, filled up, and when I pulled off the Engine Check light was off (unless it was coincidence).

[Toyota Mickey]

Hello again,

I have been told that it may be related to the fuel we use????? We tend to fill up on super market fuel ( Im sure it all comes from the same depot tanks anyway! ) but have been using BP for the last few fills just incase it was that. The light has not come on again for a while so I hope it stays that way.

Mickey

If the difference was borderline as in my case, a slightly dirtier fuel logically would push the emissions over the limit - providing the system was compromised somewhere - (obviously to a healthy system with all the emissions controls operative, it wouldn't make any difference).

http://www.bp.com/sectiongenericarticle.do...ntentId=7009013

"BP Ultimate Unleaded reduces emissions of unburnt hydrocarbons, carbon monoxide, nitrogen oxides, and carbon dioxide. The greatly enhanced cleaning power of the fuel removes carbonaceous deposits from the engine enabling it to work more efficiently which improves combustion, and in turn helps to reduce exhaust emissions."

Further reinforced by the fact I pulled into the petrol with the Engine Check light on, filled up, and when I pulled off the Engine Check light was off (unless it was coincidence).

Thanks for the info mate. Today I took out the maf sensor again and cleaned it correctly this time. It has 2 wires and they were both very dirty. they look like new now.

We had to drive up to Birmingham from Oxford today prior to me cleaning the maf and the light came on again on the way back. I had the Battery off for about 1/2 hour to reset the light so its fingers crossed time again.

Bit strange that your light went out on its own??? maybe the bulb popped?

Mickey

[uumode]

Hello again,

I have been told that it may be related to the fuel we use????? We tend to fill up on super market fuel ( Im sure it all comes from the same depot tanks anyway! ) but have been using BP for the last few fills just incase it was that. The light has not come on again for a while so I hope it stays that way.

Mickey

If the difference was borderline as in my case, a slightly dirtier fuel logically would push the emissions over the limit - providing the system was compromised somewhere - (obviously to a healthy system with all the emissions controls operative, it wouldn't make any difference).

http://www.bp.com/sectiongenericarticle.do...ntentId=7009013

"BP Ultimate Unleaded reduces emissions of unburnt hydrocarbons, carbon monoxide, nitrogen oxides, and carbon dioxide. The greatly enhanced cleaning power of the fuel removes carbonaceous deposits from the engine enabling it to work more efficiently which improves combustion, and in turn helps to reduce exhaust emissions."

Further reinforced by the fact I pulled into the petrol with the Engine Check light on, filled up, and when I pulled off the Engine Check light was off (unless it was coincidence).

Thanks for the info mate. Today I took out the maf sensor again and cleaned it correctly this time. It has 2 wires and they were both very dirty. they look like new now.

We had to drive up to Birmingham from Oxford today prior to me cleaning the maf and the light came on again on the way back. I had the Battery off for about 1/2 hour to reset the light so its fingers crossed time again.

Bit strange that your light went out on its own??? maybe the bulb popped?

Mickey

no bulb was fine, I put in some standard fuel and it came on again.

But I did notice that if the light were to come on, it came on in the first 3-5 miles or so of the journey or it didn't come on at all for that journey, which sort of indicated that the Engine Check light was tripped by a cold engine when emissions controls are possibly less well controlled than a warm engine. Anyway, I got rid of the car incase it brought expensive diagnostic repairs, as I had read of other owners changing this and that part, and more parts, and the Engine Check light still came on!

[Toyota Mickey]

no bulb was fine, I put in some standard fuel and it came on again.

But I did notice that if the light were to come on, it came on in the first 3-5 miles or so of the journey or it didn't come on at all for that journey, which sort of indicated that the Engine Check light was tripped by a cold engine when emissions controls are possibly less well controlled than a warm engine. Anyway, I got rid of the car incase it brought expensive diagnostic repairs, as I had read of other owners changing this and that part, and more parts, and the Engine Check light still came on!

Well I must say that untill today I had it in my mind that once the light came on it had to be put out either by the guys at the Toyota dealer ship with their plug-in machine or by diconecting the Battery for 15 to 20 mins. However this weekend I put some standard unleaded fuel in from the Jet garage, we had only gone about 2 miles ( caravan in tow ) and the light came on again! All weekend we have been driving around with the light on ( no caravan and then 40 miles with caravan ) Then tonight popped out for a drive and the light was out??? All very strange. I have told the Mrs to fill with BP only from now on and we will see if it come on again ( with and without caravan!!!!!!!!! )

Car stills runs like a dream with or without light on!!!!!!!!

[funkyg]

I cleaned it carefully with electronics cleaner and a cotton bud, didn't take a pic of it when it was clean but it looked like new!

Mickey

Hey Mickey!

Where did you get your electronics cleaner from? I can't find anywhere locally that sells such a thing.

Mike.

[purvesh81]

Where are both the sensors you cleaned located? I thought the avensis only had a plastic air temperature sensor that you simply pull out of the air box lid. I wouldn't mind having a look at the state of mine and giving them a clean.

ISOPROPYL ALCOHOL but which of the two?

Edited July 25, 2006 by purvesh81

[funkyg]

Where are both the sensors you cleaned located? I thought the avensis only had a plastic air temperature sensor that you simply pull out of the air box lid. I wouldn't mind having a look at the state of mine and giving them a clean.

I've been using super unleaded (optimax 90% of the time) for the past 3 years. I wonder if the build up will be anyless than yours ;)

ISOPROPYL ALCOHOL but which of the two?

To be honest, I doubt that Optimax would make any difference to the MAF as Optimax doesn't go near the air intake does it?

[purvesh81]

Yes your right. I was replying to something else I read further up and noted it in the reply above.

[Toyota Mickey]

I cleaned it carefully with electronics cleaner and a cotton bud, didn't take a pic of it when it was clean but it looked like new!

Mickey

Hey Mickey!

Where did you get your electronics cleaner from? I can't find anywhere locally that sells such a thing.

Mike.

Hi Mike,

sorry for late reply, I've been away!

I got my tin from work, it was supplied by RS. It was one of these:

RS cleaner

Hope tis helps Mickey

Where are both the sensors you cleaned located? I thought the avensis only had a plastic air temperature sensor that you simply pull out of the air box lid. I wouldn't mind having a look at the state of mine and giving them a clean.

ISOPROPYL ALCOHOL but which of the two?

Hello mate, the two sensors are down the tube of the MAF assy. I tried to take a pic but could'nt get a good one. Take your MAF out and have a good look your see them. I cleaned mine with the pressure from the aerosol only ie I didn't use a cotten bud because it all looks a bit fragile down there!

The car is working fine now and the light has not come on again . We have been using BP standard 95 fuel ( 99.9p a litre at our local in Bicester )

Good luck

Mickey

[purvesh81]

Cheers Mickey,

Could you please take a pic of where exactly in the engine bay this MAF sensor is located. I was told today my 99 Avensis doesn't have one. Which doesn't sound right as the 99 and 2000 are the Mk1 avensis

[Toyota Mickey]

Cheers Mickey,

Could you please take a pic of where exactly in the engine bay this MAF sensor is located. I was told today my 99 Avensis doesn't have one. Which doesn't sound right as the 99 and 2000 are the Mk1 avensis

Yes mate, no probs. Will do it tomorrow

Mickey

[sjrainsford]

hi purvesh81

You don't have a MAF sensor, only the VVTi engine cars have one, see here Post

A MAF sensor will mean more accurate control of fuel burning, but to be honest not having one isn't a bad thing. Less hassle!!

And hi mickey!

I think the engine check lamp goes out again if it doesn't see the fault after a set number of engine starts. Think it's sommat like three starts but not sure.

[Toyota Mickey]

hi purvesh81

You don't have a MAF sensor, only the VVTi engine cars have one, see here Post

A MAF sensor will mean more accurate control of fuel burning, but to be honest not having one isn't a bad thing. Less hassle!!

And hi mickey!

I think the engine check lamp goes out again if it doesn't see the fault after a set number of engine starts. Think it's sommat like three starts but not sure.

Cheers for that Stuart..................you learn something every day saves me posting a pic as well :D

Mickey

[purvesh81]

hi purvesh81

You don't have a MAF sensor, only the VVTi engine cars have one, see here Post

A MAF sensor will mean more accurate control of fuel burning, but to be honest not having one isn't a bad thing. Less hassle!!

Hi Stuart,

Thanks for that, I put up a post at half ten last night (Post #12, after during a review of Tech-One). As they informed me there wasn't one I thought I'd share the knowledge :D

No worries Mickey, you can post another pic of your car instead Just out of interest what did you clean if it wasn't the MAF?

[Toyota Mickey]

hi purvesh81

You don't have a MAF sensor, only the VVTi engine cars have one, see here Post

A MAF sensor will mean more accurate control of fuel burning, but to be honest not having one isn't a bad thing. Less hassle!!

Hi Stuart,

Thanks for that, I put up a post at half ten last night (Post #12, after during a review of Tech-One). As they informed me there wasn't one I thought I'd share the knowledge :D

No worries Mickey, you can post another pic of your car instead Just out of interest what did you clean if it wasn't the MAF?

I cleaned the MAF................because we have one on ours as its a vvt

I havent got one of the Avensis...........so heres one of the Supra :D