audi 90q 10v exhaust

[Duncan Thomson]

Not 100% sure, so wait for feedback from an expert, but I believe there
is a diagnostic port somewhere on the exhaust for taking O2 readings
with the car running.
But I thought this was located somewhere on the downpipe though...

Not sure, as my cars are all cat free...

Duncan

> [ Picked text/plain from multipart/alternative ]
> Whats up Quattro list. The car is audi 90q 10v
>
> My friend and I are wondering why doesour cat have a purge hole, seems
like
> its putting out excess noise.
>
> What is it for and is it ok to weld it shut? Or is there a plug or
some
> sort.