Dear A8parts, SAI picture please?

[Goran]

Hi Sergey,
the pump is dead, costs a lot from Audi to replace. Infact, costs about as much as MRC coding to code-out SAI system and post cat lambdas.
I think the longer cat life is a myth. Pre-facelifts dont have the SAI system and their cats dont seem to last noticably less. I havent seen many (any?) posts on here or quattroworld of pre-facelift cats failing.
Also, the SAI system introduces more failure points for vacuum system.
Also, the SAI system and coding causes higher revs for 30 seconds on start up. I'm wondering if this can shorten the plastic cam chain guide life, as it causes a harsher start up when oil and pads are colder and more brittle.
Of course, there is the slight loss of weight too.
I'm going to put in those nice German HJS cats again, 100 cell, since they are cheaper than stock cats and have a lifetime warranty. This also means I dont want rear lambdas, again another expensive service item.

I was just going to add, SAI is there purely for Audi to meet Euro 3 emission standard, to reduce emissions on start up when mixture has to be extra rich.
From a physics perspective, I find it hard to believe that afterburning fuel on the palladium coated cat mesh surface is good for it. Of that rapid heating is good for it.