The faster I go and then slow down, the louder the rattle noise will get. I have been told to stop driving the car, but no one has been able to tell me what should be replaced/ fixed. Here are the codes that I received from Pep Boys: P0430- catalyst bank 2, P0420- catalyst bank 1, P0300 Random miss, P0306, 6 miss P0305, 5 miss, P0154 O2 circuit, no activity B2s1, P0174 Bank2 too lean, P0304, 4 misfire, P0051 Heather control circuit low, B2s1---Also, they did not have the tools to check the timing belt and my Uncle (VW owner of 25 years)states that I should replace the timing belt, water pump, and thermostat-- before any mechanic has actually been able to look at the the timing belt. Any help would be AwEsOmE.