AO Platinum Member
Join Date: Aug 2003
Location: London, England
Re: Lambda sensor failed?
The earth point for the rear light in just below the light unit under the carpet.
Mine worked loose, I think because the boot release cable on RHD cars actually runs all the way to the NS earth point then loops back to the boot lock. I think the flexing of the boot release cable gradually loosened the earth bolt.
It is worth making sure the lambda sensor connector is clean as you mentioned.
Another cause of high lambda readings is a leak in the exhaust system, even a leak after the sensor can cause high readings.
Obviously 95000mile old sparkplugs don't help either!
Audi TT 3.2v6 DSG
xAlfa 156 Selespeed sp3 + Brembo conversion
Fiat Cinquecento 899cc