lambda sensor advice please!

Grumps

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Hi all. I've dropped the Zed of for an inspection 2 plus diff and gear oil changes this afternoon. At the last mot the emissions were sky high. (It passed, don't ask!) At lotherton last September Robert from tother side kindly plugged his laptop in and came up with a fault on lambda sensor 2. I have purchased an OEM part and asked the garage while it's there if they'll swap it for me. He asked whether it was one or two. Telling him no2 he said that wouldn't effect the emissions in any way as no2 just sends data back. Sooooooo now I'm confused? He said he'd put the probe in for me to get a reading and make sure there's no holes in the exhaust. Can anyone shed any light as to what he's saying is right? I trust him and he's always looked after all our cars but it's just the contradiction against what the computer is saying. Also he asked with it not being a standard exhaust has it been de-catted. Embarrassingly I don't know!! There's no engine management light either, it doesn't come on with the ignition so I assume some fred has taken the bulb out at some point. Sorry to blurt on, I'm done now! :thankyou:
 

Paul Rice

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Mine failed on emissions, my friendly mechanic took it for a run, emissions fine. Its the Z effect
 

t-tony

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Any holes in the exhaust won't affect the CO reading Dave but will affect he Lambda ( which, in the old days was called air/fuel ratio) The 2nd lambda sensor measures oxygen in the gas after the cat and the OBC compares the readings of both before and after the cat to then alter fueling. IF your car has had the cat removed it becomes a bit awkward for the tester. A blow after the 2nd O2 sensor raises the O2 level in the exhaust gas and the car may fail the test. No. " does send data back, but if it's faulty it can send wrong data back so chances are good old "R" is right.

Tony.
 

Grumps

Always happy, apart from when I'm not 🤬
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Forest Town, Mansfield
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Any holes in the exhaust won't affect the CO reading Dave but will affect he Lambda ( which, in the old days was called air/fuel ratio) The 2nd lambda sensor measures oxygen in the gas after the cat and the OBC compares the readings of both before and after the cat to then alter fueling. IF your car has had the cat removed it becomes a bit awkward for the tester. A blow after the 2nd O2 sensor raises the O2 level in the exhaust gas and the car may fail the test. No. " does send data back, but if it's faulty it can send wrong data back so chances are good old "R" is right.

Tony.
Thanks for that Tony. That makes more sense to me. I'll speak to him tomo.
 

t-tony

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You're very welcome mate.

Tony.
 
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