Avensis Emissions Problem

[Jin Kazama]

Hi everyone, wondering if anyone could help me. I have a year 2000 avensis 1.8 vvt-i which recently failed its MOT test because of failing the lamda and CO emissions test. I have changed the catalyst converter which made no difference. Then i changed the 2 sensors on the top part of the exhaust which fixed the lamda problem. So the CO test is still failing. I then replaced the bottom sensor on the exhaust but still have the problem. Anyone know why the CO test is failing and how I can fix it?

[jed50]

Hi everyone, wondering if anyone could help me. I have a year 2000 avensis 1.8 vvt-i which recently failed its MOT test because of failing the lamda and CO emissions test. I have changed the catalyst converter which made no difference. Then i changed the 2 sensors on the top part of the exhaust which fixed the lamda problem. So the CO test is still failing. I then replaced the bottom sensor on the exhaust but still have the problem. Anyone know why the CO test is failing and how I can fix it?

I had same problem last year but lambda sensors cured it. This year though is a different story! I have same year car and engine. So far the car has cost me £800 and still not cured or mot'd. Throttle body seal replaced, vacuum pipe to servo replaced, spark plugs replaced, cat replaced, lambda sensors replaced, timing chain, tesioner, vvt unit on cam sprocket, all replaced and all this done on the recommendation of toyota technical helpline. My garage has now been told by them that it could be a wiring fault or the ecu (£680). Sorry if this is not much help but I just thought you should know what you are letting youself in for! Love the car, but wont get another petrol, diesel next time.

[mavrik2k3]

Hi everyone, wondering if anyone could help me. I have a year 2000 avensis 1.8 vvt-i which recently failed its MOT test because of failing the lamda and CO emissions test. I have changed the catalyst converter which made no difference. Then i changed the 2 sensors on the top part of the exhaust which fixed the lamda problem. So the CO test is still failing. I then replaced the bottom sensor on the exhaust but still have the problem. Anyone know why the CO test is failing and how I can fix it?

I had same problem last year but lambda sensors cured it. This year though is a different story! I have same year car and engine. So far the car has cost me £800 and still not cured or mot'd. Throttle body seal replaced, vacuum pipe to servo replaced, spark plugs replaced, cat replaced, lambda sensors replaced, timing chain, tesioner, vvt unit on cam sprocket, all replaced and all this done on the recommendation of toyota technical helpline. My garage has now been told by them that it could be a wiring fault or the ecu (£680). Sorry if this is not much help but I just thought you should know what you are letting youself in for! Love the car, but wont get another petrol, diesel next time.

sorry if this is classed as stealing your thread,,,but sort of the same problem with me at at the mo..car a 2001 avensis vvt-i 1.8 gsr...mileage 94k ...long winded this may be, but more info the better i guess.

had a mil light on for a while,,had it read,,,have my own reader

2 faults keep coming up

P0171 generic system too lean (bank 1)

P0174 generic system too lean (bank 2)

MOT time ..car failed on emmissions,,,took it to another guy ,,,er and got it passed ,,,nudge nudge, but of course the problem is still there, put it on a friends Horiba emmisions machine,,it reads 3.7% which is a fail.

another friend done a cut and shut with a brand new Cat from another make of car. all good and shiny !

put it back on the Horiba machine...now reads 0.1% :) good for the emmisions , but does not fix the fault in the first place. ive cleaned the MAF sensor and it seems to run a little better i will now being going the route of messing with o2 sensors, what i am asking is this the route to take ? or a good start ,,and as there are 3 ..dont realy want to pay Mr T for the pleasure, as i know they wont test and just change all 3 and charge for it ...are the aftermarket ones any good ? or can someone point me to a link where they have purchased some that have done the trick. andmaybe also a new MAF sensor as well.

it may be worth noting that it was very black in the intake of the exhaust which i wa told it is running very lean.

i have read threads on here much about the same thing but cant recall one that at the end says all if fine with the car now and thanks for the help..

Mavrik

[jed50]

Hi everyone, wondering if anyone could help me. I have a year 2000 avensis 1.8 vvt-i which recently failed its MOT test because of failing the lamda and CO emissions test. I have changed the catalyst converter which made no difference. Then i changed the 2 sensors on the top part of the exhaust which fixed the lamda problem. So the CO test is still failing. I then replaced the bottom sensor on the exhaust but still have the problem. Anyone know why the CO test is failing and how I can fix it?

I had same problem last year but lambda sensors cured it. This year though is a different story! I have same year car and engine. So far the car has cost me £800 and still not cured or mot'd. Throttle body seal replaced, vacuum pipe to servo replaced, spark plugs replaced, cat replaced, lambda sensors replaced, timing chain, tesioner, vvt unit on cam sprocket, all replaced and all this done on the recommendation of toyota technical helpline. My garage has now been told by them that it could be a wiring fault or the ecu (£680). Sorry if this is not much help but I just thought you should know what you are letting youself in for! Love the car, but wont get another petrol, diesel next time.

sorry if this is classed as stealing your thread,,,but sort of the same problem with me at at the mo..car a 2001 avensis vvt-i 1.8 gsr...mileage 94k ...long winded this may be, but more info the better i guess.

had a mil light on for a while,,had it read,,,have my own reader

2 faults keep coming up

P0171 generic system too lean (bank 1)

P0174 generic system too lean (bank 2)

MOT time ..car failed on emmissions,,,took it to another guy ,,,er and got it passed ,,,nudge nudge, but of course the problem is still there, put it on a friends Horiba emmisions machine,,it reads 3.7% which is a fail.

another friend done a cut and shut with a brand new Cat from another make of car. all good and shiny !

put it back on the Horiba machine...now reads 0.1% :) good for the emmisions , but does not fix the fault in the first place. ive cleaned the MAF sensor and it seems to run a little better i will now being going the route of messing with o2 sensors, what i am asking is this the route to take ? or a good start ,,and as there are 3 ..dont realy want to pay Mr T for the pleasure, as i know they wont test and just change all 3 and charge for it ...are the aftermarket ones any good ? or can someone point me to a link where they have purchased some that have done the trick. andmaybe also a new MAF sensor as well.

it may be worth noting that it was very black in the intake of the exhaust which i wa told it is running very lean.

i have read threads on here much about the same thing but cant recall one that at the end says all if fine with the car now and thanks for the help..

Mavrik

Hi Mavrik, Ive heard that non toyota o2 sensors are ok but also ive heard that they dont last as long as toyota ones though! Sorry, dont understand the 'black in the intake of the exhaust' bit. The intake of the exhaust is not normally visible due to it being inside the engine, but if it was black it would not be lean, it would be running rich! Another trick I heard about was change the oil and filter......must be something to do with the sealed crankcase system? I would give that a go though! Where do you get these emission machines from? I could do with one of them so I dont have to keep paying garage to check it! Im seriously thinking about getting rid of the car (it has cost me over £2500 in the last 14 months!) Its a diesel next time!

[uumode]

Just wondering if you guys use a petrol additive, or if you use the supermarket fuels?

[Penfold]

for the old style leaded fuel you expect light grey/brown for a correct mix to show in the exhaust but only after prolongued motorway running.

unleaded fuel always presents as black no matter what.

If you have changed the Cat and all of the sensors then try a cylinder compression check and monitor your oil usage. you could be burning oil slightly - just enough to tip the balance against you.

[mavrik2k3]

for the old style leaded fuel you expect light grey/brown for a correct mix to show in the exhaust but only after prolongued motorway running.

unleaded fuel always presents as black no matter what.

If you have changed the Cat and all of the sensors then try a cylinder compression check and monitor your oil usage. you could be burning oil slightly - just enough to tip the balance against you.

ahh need to explain a bit more i think...ive got one of "them" engines that use a fair bit of oil...had all the messing with Toyota last year ,,with no joy.

sorry the black look of the exhaust was at the view down the pipe from after the warm up cat.

so the car does use oil...a mixture of supermarket and garage fuel...and not a lot of motorway driving, more the school run sort of thing.

the tester i have ,,is very good , cost £75 from ecufix.com

the emmissions tester ,,,well a lot more expensive and was borrowed.

will try a filter and oil change as that will never do any harm,,whether it needs it or not,

i'm going to go that route before the 02 sensor i think..cheaper for a start !

having reset the trouble codes and turned the engine light off ,,,only done 16 miles down the road and it was back on again :( but the Cat has sorted the emmissions for sure ..just need to find the other problem now .

cheers Mavrik