Toxic warning light

[Joethrelk]

Just been on a day out to alton towers. After about 100miles i got a toxic warning light apaear on the dash. Car doesnt seem to have lost any power and is still running fine. My first thoughts are that it is my decat that has caused this even though it has been in the car for 4 months and has never caused a problem.. Anyone got any idea how to get rid of it. If i disconnect the second sensor from the decat how do i reset the computer.. Please help

 

[Lunner]

Take the bulb out ;-)

 

[Da]

or the fuse (if there is one?)

 

[1.6 16v]

My toxic fume warning light came and i took to renault and they changed the plugs. £124 and renault paid 75%

 

[Joethrelk]

any other ideas??

 

[JAY172]

you cant reset the obd fault memory yourself. you would need a renault dealer to erase the fault and then leave the second sensor disconnected after that.

 

[Joethrelk]

Do you think this would solve the problem. Is the second sensor the reason it has lit the warning light?? Seems strange it has taken four month to arrise i have done about 4000miles with it on..

 

[Big Iain]

this exact same thing has jus happened to me on the way to the scottish meet!!

 

[JAY172]

it might have took a long time but the obd system checks the cats operation using the second sensor. the test conditions have to be that exact that the test isnt completed that often and it has to fail 3 times before the warning light comes on. on a long steady run your more likely to be under test conditions (steady rpm/throttle setting for at least 30 seconds) so it is able to complete 3 tests and so the light has now come on. if the 2nd sensor is disconnected these tests cant be carried out by the obd. the obd has 3 faults in its memory now and you need the dealer to erase them.

 

[Big Iain]

so if you rag the arse of the car all the time it wont get a chance to test it?? funny that since tonight was the first time I used cruise control since I got the decat fitted!!

 

[clio_lass]

The same thing happened me - twice!

First time i just took it to renault as it was under warranty and they said my lambda sensor had gone faulty

Second time the car lost a LOT of power, could barely move, sounded like a scooby! lol - took it back to renault and they said one of my spark plugs had been faulty.. hmm...

 

[WeeGad]

I get this happening to but its because my ignition coils keep going,also when this happens my clio goes into "tractor" mode in which it sounds and picks up just like a tractor and uses up loads more petrol

 

[JAY172]

Quote: Originally posted by Big Iain on 23 May 2004

so if you rag the arse of the car all the time it wont get a chance to test it?? funny that since tonight was the first time I used cruise control since I got the decat fitted!!

basically yes but you cant rag it all the time. there will always be a point where your just cruising. normally it can only self test between 2500rpm and 3500rpm under light throttle conditions.if you have a decat just unplug the 2nd sensor.

 

[ebee]

you will find that if the light stays on solid, then the fault is more than likely from the upstream lambda sensor ( the one before the cat ) and if it flashes, it is the downstream one, past the cat, as the flashing indicates what is assumed to be destructive misfires... or in the case of a decat, it realises there is no change in fumes from sensor 1 -> 2 which in turn signals a fault with the cat...

i had this problem the other day, and it has now cleared after some mucking about...

by the way, if the fault is not detected in 40 consecutive cold starts, the fault is removed from memory, it takes something like 3 consecutive sucsessful tests for the light to extinguish...