Stevey Y

Hi it depends what type of filter housing you have if the new filter just plugs into the cap without a plastic tower running through the middle you wont need the smaller o ring.
Steve.

Hi yes anything that looks like its sweating is bad news.
Steve.

Hi go on to LLL carparts website put in your vin and search sensors it will throw up a diagram I believe there are three, one before the cat one after and one a lot further back assuming your model has the second Adblue injector station on the lower part of the exhaust.
Steve.

Hi yes they do degrade over time and when they start to die completely they go pink, if yours are the original bulbs they are either 3200k or 4200k, you can upgrade to 5500k or 6000k with a very noticeable brighter light my preference would be 6000k as this is a sharp white light, look on a site for valley lighting, you may be well served changing the ballast units as well as they can also degrade.
Steve.

Hi its the motor in the washer bottle fairly easy to change and the part wont break the bank unless you buy a genuine part.
Steve.

Hi LUK/SACHS not much choice really as LUK own SACHS but SACHS are a little bit cheaper.
Steve.

Hi firstly Cliff its used to clean the the backs of the valves inlet/exhaust via the cylinder head ports which involves removing the manifold originally designed for Diesel engines.
If you have a petrol engine you will never need it and personally I have run my Diesel engines way over the specified life span of the engine and never needed it, dont know where you were told this but tell them not to give up the job at Jackanory.
Steve.

Hi the only problems that occur with adblue crystals is when its out of the container thats over two years old or its been sitting in the car for over two years which is nigh on impossible, any way whatever you get treat it to a bottle of crystal dissolver [Forte] is good, these cars do not like cheap adblue and especially supermarket fuel, if you want total peace of mind with adblue buy a Peugeot or a Citroen they use pats fluid, ELOYS.
Steve.

Hi from my perspective you would be better off with the original D2s the service life for LED units aftermarket is probably less than the HID because %99 of them are Chinese and for some peculiar reason have cooling fans attached to them, the D2s works straight out of the box, LEDs do create more heat and annihilate the beam pattern, So if you want a cheeky upgrade go for 5000-5500 kelvin D2s no extra heat just a whiter light, try Vally Lighting on eBay, I used their D5s units, fair price and only got a bit dim after two years and 100,000 miles [cab working nights].
Steve.

Hi if you are swapping to a buttoned wheel from non buttoned you will need the donor wheel and associated wiring loom and possibly another body control module which will leave it needing to be coded in to the new BCM to get it to work.
Steve.

Hi have you tried resetting the level on diagnostic equipment, only suggest that as what you have posted leans towards that, absent any code numbers its the only conclusion that can be drawn from the information supplied, the board is housed under the tank and can't be replaced as far as I am aware.
Steve.

Hi it needs calibrating and coding again with VCDS or OBDEleven even if you bought a brand new unit from Audi it would still need the same, I suspect the garage did not lock the entering of the steering wheel when they fitted the rack it only has to be one tooth out to throw up the lights.
Steve.

Hi ATE is good so we have to work back from there provided the spring clip is present the next thing is the plug that joins the the sensor cable to the loom, was this difficult to remove?, I had this recently where the plug was difficult to remove and the pins inside the female part of the plug [main loom] were displaced and corroded, cured this by buying a repair kit on eBay as this is apparently quite a common problem, I priced the upper loom which you can only buy from Audi at over £200, so I opted for the repair kit at £9.99 from a company called Just German Parts on eBay its a doddle to fit and just required soldering to the main loom, word of advice just twist the wires together before soldering to make sure you have the wires the right way round and the light is out.
Steve.

Hi I have been watching this post carefully, if for the price and the milage was a steal this car would have gone about ten minutes after it hit the forecourt, all the cars I have ever bought have been for the most part from private vendors as the majority only want to sell the car with no come back so generally they tell the truth, oldest saying in the world, how do you tell when a car salesman is lying?,his lips move.
Steve.

Hi pull the engine cover off and the tube is about half way down on the right you can't miss it as it has a loop fitting on the top, to remove it twist and pull.
Steve. 

Hi Terry yes the OBDEleven is a first class tool for the average Diyer  and at around £100 with a bundle of tokens it will save you a fortune in the long run, you can code pretty much anything on the car that you have replaced, read and clear faults, in fact it will pay for itself a thousand times during your ownership and if you dont quite understand the codes come back here, WIN,WIN. You can even reset your rear handbrake perimeters.
Steve.

Hi it could be down to a blocked filter, these need to be changed every 30-40k if its struggling to pull the pressure required it will be sluggish, can't get my head around just changing the oil, its like changing the engine oil and leaving the old filter in there.
Steve.

Hi try ebay, about £40 a set.

Hi the only thing I would personally change is the glow plugs, as for the loom just get it checked in other words if it isn't broken don't fix it, the glow plugs are probably well past their sell by date and well worth changing as they contribute a lot to engine function especially on start up on colder days as it stops unburnt fuel from killing the catalyst.
Steve.

Hi the only thing I have ever used on any bolt I have re used is a dab of blue thread lock they wont move with that on them, I get fed up with all this rumour spreading about stretch bolts the rule of thumb being anything to do with the engine, clutch, timing belt you use new bolts, anything else provided the thread is good can be reused.
Steve.

Hi the most common cause of this is people grease the backs of the pads most brake pads come with an anti squeal pad on the back of the pad its like a film of rubber which when the pads are first used bonds the pad to the surface of the calliper stopping the pad from moving, therefore if you have greased that surface they move when the pads are released and squeal.
Steve.

Hi go on a site called ZAP 7 and put in your VIN that should bring up a parts catalogue for your car, the part number is the key to getting the right part and YouTube is the best source of how to if you are unsure how to fit the part.
Steve.

Hi pretty straight forward if you look at the second picture the tab in  front of you has no locking hook, that is the position tab which is lower and wider than the rest so if you find the reciprocal slot on the vent once located it should just push in.
Steve.

Hi it looks like the PCV valve has become broken/disconnected and is spraying crankcase gas and oil vapour over the engine, the part wont be that expensive and I should imagine about an hours labour easy fix.
Steve.

Hi not wishing to appear stupid but is the pump the right way round as it should have a flow arrow on it.
Steve.