Lamba sensor fault? help please

[shep1001]

The car is a little poorly I wonder if somebody can help.


EFI code 4 fault flashes up then clears on start up. Plugged into the diagnostics its showing as Lambda2 fault (1.8V so I assume it defaults to open circuit). Must have gone on the way back from Alton Towers today.

1) If (assuming you can and its safe) I swapped the plugs for lambda1 & lambda2 over and the fault swaps banks it points towards the sensor yes?

2) Is it safe to drive like this (don’t want to damage the cat) as I will have to take it down to Str8six to get it replaced (about 60 miles) as I don’t have a ramp/pit to get under the car, IIRC they can be an arse to change anyway


Thanks in advance

shep

Edited by shep1001 on Tuesday 10th May 18:35

[PetrolHeadPete]

If fault moves then yes seems pretty deffo
Wouldnt leave it like that else both banks will run wrongly
One lambda for each bank of 3 cylinders so if you change it over it will be trying to adjust
Mixture based on readings of exhaust for the wrong 3
If it runs very lean it can damage the cats and even cause bits to go back into the engine if cat disintigrates

Get new one asap

[shep1001]

PetrolHeadPete said:

If fault moves then yes seems pretty deffo
Wouldnt leave it like that else both banks will run wrongly
One lambda for each bank of 3 cylinders so if you change it over it will be trying to adjust
Mixture based on readings of exhaust for the wrong 3
If it runs very lean it can damage the cats and even cause bits to go back into the engine if cat disintigrates

Get new one asap

Just been out to check it again and the lamba fault cleared when I fired her up, the voltage dropped from 1.7v down to less than 1v, whereas before it was just a static reading of 1.75V. Readings for both sensors fluctuate now from about 0.23V upto about 1.3v depending on throttle position

There is however quite a difference in the adaptive readings between banks. Might get it looked at just to be sure.

Shep