I have a 1999 a4 1.8T Quattro and lately it just drive like a piece of crap. The car shakes really bad when the weather is above 90 degrees both when being driven and when it is idle. Engine check light came on and reads the following codes-
P0300-Random /multiple cylinder ,isfire detected
P0303 Cylinder 3 Misfire detected
P0304-Cylinder 4 Misfire detected
P0302 Cylinder 2 Misfire detected
P0422 Main Catalyst Below Threshold (Bank 1)
P1300-Manfacturer Contrl. Ignition System or Misfire

If anyone could please help me with these codes so perhaps i can fix them by myself. Thanks