Had the car on conzult and its showing no reading from the o/s o2 sensor, is this likely to be the sensor broken or dodgy wiring? The car is going for a MOT soon, will this cause it to fail due to emissions?

No reading or no changes ? I seem to recollect that if the sensor is disconnected then a default voltage is still displayed.

 

This is quite likely to cause an MOT failure because I think a faulty sensor will usually result in the engine running rich and therefore high emissions.

No reading or no changes ? I seem to recollect that if the sensor is disconnected then a default voltage is still displayed.

 

This is quite likely to cause an MOT failure because I think a faulty sensor will usually result in the engine running rich and therefore high emissions.

 

It says no reading from sensor?

I had this fault.the sensor has 3 wires.a red/back common feed which is used on all the engines sensors,a black wire for the earth and the middle wire is the shielded wire which relays information to the ecu.check it has a live and an earth.then youll need to check the middle wire has continuity and is insulated from earth.the middle shielded wire is like co ax cable.the outer shielding is earthed.mine had a short from the inner to the outer earthed wire.if you have a multi meter connect it to the middle wire and run the car at 2000rpm.you should see the voltage rise and fall rapidly.Andy is correct in saying that the de fault when the ecu sees no reading from the lamba is to run rich.a lean mixture would damage the engine.

check the connector - they get green oxide disease - common on zeds - give them a good scrape and run the diagnostic if the consult is not handy - it will show if they are both operating. I thought I had a dead one till I checked the connectors.

This is quite likely to cause an MOT failure because I think a faulty sensor will usually result in the engine running rich and therefore high emissions.

 

would this suggest that a small inline resistor at MOT time could infact trick the engine to running rather lean?