Hello, I have a 1999 Audi a4 quattro AWD 1.8T. So here is what happend, I was driving on the highway going about 65ish in 5th gear and then my rpm's drop and my audi start losing power. I pulled over on the side of the road and shut off the car, I started it back up but then it just died on me. I changed out the fuel filter ( which was disgusting. ) I put a brand new one on. Now I can get it to start, but the only way it will keep running is if I keep the rpm's above 2500. After the rpms drop the car dies again. Anyone know what the problem might be..? Any advice on this would be be helpful. Thank you!