Google much? p0430 is an o2 sensor, p0420 also has to do with o2 sensor, p0303 is a cylinder 3 missfire start with plugs.... p0205 is cyclinder 5 misfire change the plugs... I havent kept up with your other post, what exhaust setup are you running and how long...? Might need to check out the o2 sensors may need to be replaced.
