Changing Lambda sensor

[JamesHarrold]

Picked up a new Lambda sensor today....
Is it advisable to disconnect the battery before fitting it and/or reset the ecu?

Cheers
James

[A80Avant]

if you dont have VAGCOM to do it,best to just replace it and leave the battery off for 10mins

[JamesHarrold]

Thanks for that....will do...

James

[AUDIS2avant]

is 10min enough???

[HPmuirt]

OK, am I the only one who does not fully understand why you need to reset the ECU after a lamda sensor change?

I assumed the fact that the ECU is a 'learning' one would mean that it would adapt to the new readings received.

Cheers n

Si

[Jonas_R]

Could be because a defective lambda sensor has left a fault code and that need to be cleared.

[JamesHarrold]

Dont have a fault code stored for lambda, just that the car is running like an old tractor, struggles to start sometimes and cuts out occasionally....and fuel economy is pants....changed pretty much everything on the car since I bought it a year ago (as many of you will know from previous threads!)

James

[Avanter]

Even 20 min i my case are not enougt... fault code clerence are sucesiful only with VagCom.

[s2_bo]

You can clear the fault codes in minutes, just pull out the two motor fuses in the fuse box for about 2 minutes.

Job done.

[Bowlerwell]

OK, am I the only one who does not fully understand why you need to reset the ECU after a lamda sensor change?

I assumed the fact that the ECU is a 'learning' one would mean that it would adapt to the new readings received.

Cheers n

Si

I Agree.
Do I really need to disconnect the battery so that the ECU 'learns' properly again?
Or will a straight replacement work?

Thanks,
JohnB

[prj]

These ECU's reset the MOMENT pin 18 is disconnected from the connector.
All this talk of 20 minutes is hogwash, there are no big caps inside, no batteries.

Just replace the thing, it'll adjust the trims on the fly.
No need to disconnect anything.

[Bowlerwell]

Just replace the thing, it'll adjust the trims on the fly.
No need to disconnect anything.

Thanks Dmitri

[20Vcqdriver]

Might also be worth putting an m18x1.5 tap down the hole before fitting the new one. I almost cross threaded mine a few years back and this last time re-tapped the hole and it went straight in...

[Bowlerwell]

Is it supposed to look like this, or does all the charring indicate a problem?

Sent from my HTC One X using Tapatalk 2

[UrS4boy]

Is it supposed to look like this, or does all the charring indicate a problem?

What you have there, my son, is a dead parrot, not just one pining for the fjords.