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Lamda sensors

Posted: Sun Mar 08, 2026 10:34 pm
by Mckillop
Hi, I have got a engine check light for catalytic efficiency low.
So I have been looking at the catalytic converter and it appears that I don't have a pre cat fitted.
It's a scirocco 2009 2.0tsi Cawb engine.
I am led to believe that all these cars have 2 cats one pre cat and one post cat.
So I have been looking everywhere for the pre cat electrical connector thinking that someone might have removed the lamda sensor. But I can't find one anywhere.
Can someone tell me is it normal to have just the post cat fitted.
Many thanks

Re: Lamda sensors

Posted: Mon Mar 09, 2026 11:20 am
by 1.4_tsi
Looking at the parts diagram, the CAWB engine only has one lambda probe, though it lists it under the "in front of catalyst" heading, with nothing under the "behind catalyst" heading, which is odd.

The part number is 1K0998262E, list price £238.50+VAT, though there seem yo be plenty of aftermarket alternatives