I bought a 2002 Audi TT that I get a P0171 Code on and off. It does not seem to cause the engine any problems. Yet the code comes on and off. I talked with the previous owner and his comment it does it once in awhile when it has sat for awhile, claimed old gas. Well I use the car daily and once or twice a day I get the code and then clear it but it does not come on all the time. It is the 1.8L Turbocharged.1.8L 1781CC l4 GAS DOHC Turbocharged