Feel duty bound to reply.
Interesting, not what I expected, almost clever. I am not an expert and I am struggling to understand the effect of bypassing the N316 valve and how the flaps will behave. Anybody? One thing is certain, the ECU can now no longer control the flaps, it will realise and run the engine in homogenous mode (and light the EML). This could have been achieved simply by unplugging the N316 electrical connector and not bothering with this deviousness. Sorry not much help and stating the obvious that it must all be put back to rights.
To this end on the positive side the cost of a new N316 valve (part number is
037906283D) is not that bad at £47, or used from £10 on eBay but I would not go there, but
@A2Steve is currently recycling a FSI and I am sure he can provide any parts you need for a few pounds. It's only the size of a matchbox (+ electrical connector socket) and I believe Pierburg were the original Audi oem provider, and I recently recently bought this
Find many great new & used options and get the best deals for Pierburg 7.28098.04.0 Air Intake Control Valve at the best online prices at eBay! Free delivery for many products!
www.ebay.co.uk
You/your mechanic will also need two M5 x 16 mm pan head bolts to attach the valve to the manifold, such as this
These are a DIN 7985. Further details are as follows M2 M2.5 m3 M4 M5 TORX PAN HEAD MACHINE SCREWS. Thread Size - M2 (2mm). A2 STAINLESS STEEL. Thread Size - M2.5 (2.5mm). Dowel Pins & Lynch Pins. Thread Size - M4 (4mm).
www.ebay.co.uk
[Does not have to be stainless]
You have not said if the small rubber tubing that attach to the valve are still present, if not you will have to source these, part numbers
036133784K and
036133784J, or make your own. I just hope the electrical is just dangling somewhere.
With the parts at hand I cannot see it taking very long to reinstall the valve say 1 hour labour max.
Slight note of pessimism but as I said before unless a faulty valve was the original problem leading to the bodge then this in itself may not clear the flap fault, but certainly part of the solution if not.
Hope this helps.
Andy