hilltop car care

Please I need your suggestion. Am currently working on a Toyota Avalon 2008. It was not starting so I did a diagnosis and got the error code P0335- Crankshaft Position Sensor 'A' Circuit Malfunction and P0102 - Mass or Volume Air Flow Circuit Low Input. I cleaned up the CKP sensor, same issue and I went ahead to replace it,replaced the air filter, I discovered the engine oil was very dirty and due for a change, I had to do that, the fuel filter was cleaned up. After all that the car came up, was fine for some time and went off again. I did another diagnosis and got P0393 - Camshaft Position Sensor 'B' Circuit High Bank 2. All this while the check engine light was still on. We noticed a cut on the cam shaft sensor and tried amending it. The car came up, was on for 15 minutes and went off again. Right now when you turn on the ignition all the dashboard lights comes up exclusive of the check engine light. What could be the likely cause?