Put a mechanical oil pressure gage on the engine. I expect you will find you have very low oil pressure. If the idle pressure is 10psi or lower, it is a sure sign that you have damaged the bearings in the engine. This is a classic sign. The P codes 12 and 24 are telling you that the vvt gear is not working correctly. This is usually due to low oil pressure. Replacing the solenoids did not fix the root problem. It is likely that the engine was damaged by letting the oil level get too low at some point. Damage could be to Engine main bearings, rod bearings or cam bearings. P430 tells me that your catalytic converter is not functioning correctly. This can be caused by excess oil consumption fouling the converter. Does this engine consume oil? How many miles are on it? It is doubtful that it is worth fixing as these problems point to a history of poor maintenance or advanced age. Given the low oil pressure, the engine will sooner or later grenade. If you like the car, a used engine replacement could be an option, but you are looking at $3000 or more to do so.
