2002 Audi A6 3.0 V6 not a Quatro. DIY oil and

where does it leak from, investigate, you may need to tank, could be hoses. Unable to investigate take to repair shop.

need to do a smoke test done to see if and where you have a vacuum leak, could also be a bad cat.

Fuel filter, TPS sensor, clean throttle body.

unhook battery positive and install test light in between the post and the cable. if it has a draw it should come on dim. then unplug the fuses one at a time and when you pull the fuse and the light gose out thats the circut with the draw. then refer to what that fuse runs and correct the problem by inspecting that part and repairing as needed.

Hi!!
Five qts. is what it takes. Ask the autoparts tech what is the recommended oil for your vehicle based on the yr and mileage.
Good Luck!!

check fuse

yes the whole subframe needs to be dropped as an assembly to do this job..2.7t is an awesome engine but not very user-friendly to work on.

he has enouf oil.

The best balance of price, quality, availability that I have found is Mobil1 synthetic - it's on Audi's approved oils list. With the 2.0T engine, you absolutely want to use synthetic (the Audi turbo fours are known for oil sludge issues), and you want to do a SeaFoam treatment every 15k miles or so - that combination will keep your engine in great running shape.

I also have a 2004 Audi A4 3.0 Quatro and the low oil sensor comes on periodically. I pull the oil dip stick and put it back and it goes away. Maybe it will work itself out.