Malfunction indicator lamp came on when I accelerated harshly

It had come on a few weeks back but it was diagnosed as a "damp" lambda sensor. Once is was reset it came back on a week later for a few minutes, then was gone for about a month until tonight. I took the car out from a cold start and after about 15 minutes of driving was accelerating rather strongly to overtake and the light came on immediately and wouldn't go out, didn't notice the car driving or sounding differently afterwards but it's playing on my mind as to what it may indicate. Any ideas?

I'm driving a 00 1.4 vvti Corrolla (Otherwise known as an irish special).

Senna

Have you noticed any decrease in MPG? Has the sensor been changed? if not just get a new one, they can be fairly cheap on the net and they're easy to change yourself if you can get under the car.

Senna

Senna wrote: »

Have you noticed any decrease in MPG? Has the sensor been changed? if not just get a new one, they can be fairly cheap on the net and they're easy to change yourself if you can get under the car.

Haven't noticed any change in MPG really, stays around 34+ driving 10 min trip to work. The sensor wasn't changed last time so maybe that's what it is, though you think the lambda sensor tripped when I accelerated harshly?

mondeo

Sounds suspiciously like my Mums Peugeot 207 earlier in the year. A new ECU in her case solved the problem.

dougie-lampkin

Sacramento wrote: »

I took the car out from a cold start and after about 15 minutes of driving was accelerating rather strongly to overtake and the light came on immediately and wouldn't go out, didn't notice the car driving or sounding differently afterwards but it's playing on my mind as to what it may indicate. Any ideas?

Sounds like either the cat or second lambda to me. If the ECU doesn't see a reduction in emissions across the two lambdas (ie, the cat is working), it'll throw up a CEL, even though you'll have no difference in economy or performance.

To test, take out the second lambda, and cable tie it out of the way in the engine bay. Blank off the boss in the exhaust with an M18 bolt. Now try and replicate the problem. The second lambda will be reading clean air, which will be inevitably cleaner than the exhaust passing the first lambda. If the light comes on, I'd lean towards the lambda being faulty, if it doesn't come on, I'd lean towards the cat.

dougie-lampkin

dougie-lampkin wrote: »

Sounds like either the cat or second lambda to me. If the ECU doesn't see a reduction in emissions across the two lambdas (ie, the cat is working), it'll throw up a CEL, even though you'll have no difference in economy or performance.

To test, take out the second lambda, and cable tie it out of the way in the engine bay. Blank off the boss in the exhaust with an M18 bolt. Now try and replicate the problem. The second lambda will be reading clean air, which will be inevitably cleaner than the exhaust passing the first lambda. If the light comes on, I'd lean towards the lambda being faulty, if it doesn't come on, I'd lean towards the cat.

Wow thanks for the help but I reckon this is way out of my league repair wise. My friend will have a look at it soon for me like he did last time, he can get it code read and check the sensors. I'm hoping it is the lambda sensor again as that would make sense in relation to what it was last time, but it's just the manner in which it came on that concerns me, right on when I put the boot down. However, that might be what a mechanic would expect it to do if there is a faulty lambda. I'm just not there yet knowledge wise as I've only had this car (my first) for just under 2 months. I certainly hope it's not the cat!

Is it easy to reset the warning light so that it comes on again if the problem is still there or not if it's gone?