My 2008 Audi A3 starts but wont stay on

pull the plugs and check for spark it might jsut be a coil issue.

Replaced all plugs and coil packs and drive it for about 100 miles and checked the plugs again and they are covered in black carbon.

These are the codes it's throwing.. P2293 p2440 p2570 p2569 p0491

P2293 is fuel pressure, p2440 is Secondary Air Injection System Switching Valve Stuck Open, p2570 - p2569 is Direct Ozone Reduction Catalyst Temperature Sensor Circuit High, p0491 is Secondary Air System Bank 1 & 2. In short first off the car simply put is not firing properly and the fact you were driving it during this time has likely killed your catalytic converters. Some of the breather hoses are likely clogged as well find the stuck air valve and replace it it will likely be the cause of the fuel issue. I would replace the fuel filter as well as this can some times cause this issue as well if it is full of crap. The idea is to solve one issue at a time working from the first trouble code to the next the reason for this being usually the first code is where the main issue is.

Issues were fixed put now the car is throwing codes P2570 and P0299. Their are saying it has to do with a sensor on the radiator and the turbo underfoot I think might be the cat....any thoughts? This car is a pain

This is most likely a cat issue. Either the cat has gotten pluged or its gone bad. This is often caused by backfiring issues poor idle exctra. I would first try checking all the sensors clean them check the wiring and listen to your turbo. If you hear any sign that it is struggling then you most likely need to replace it. These cars do get to be a bit of a money pit after they get old but then again what car isn't. I did most of my repairs myself and it saves your wallet alot of money doing so. if your turbo needs replacing tho i would recomend a garage doing it as it is a pain in the ass and the turbo regardless is any where from 600 - 900$ and only buy a new one never a used one.

Ya next thing I'm going to replace is the cat. And both o2 sensors. Turbo sounds fine. No issues with it.