Q: Codes P0201 & P0301 are being read immediately after local instant oil change garage overfilled engine with oil.

After driving less than a 1/4 mile from the oil change garage black smoke began to come from the car as the car began to shake violently. Pulled to the side of the road and the garage mechanic drove out and confessed to overfilling the engine with oil. They drained all the oil out then put the "proper" amount back. The next day the engine light began to blink as the car again shook violently until it cut off on its own. This happened for the next three days. The area manager for the oil change garage stated that the codes were purely an electronic issue and what I was experiencing had nothing to do with them overfilling it with oil. Since they refused to take responsibility, I took off the upper manifold intake and inspected the fuel injectors and spark plugs. Oil was found in both female and male ends electric connector to the fuel injector that corresponded to the codes. I took pictures and sent to the manager. He still claims no fault. Could their error be the cause?

My car has 175000 miles.
My car has an automatic transmission.