The P2316 engine code seems a kind of powertrain problem and this problem is easy to fix without changing any part or adding any part in the car engine. So, you do not need to expense more money. You can fix the car engine at cheap rate. You need to check the check list Throttle/Pedal Position Sensor/Switch A Circuit Intermittent, Injection Pump Fuel Metering Control ‘A’ High (Cam/Rotor/Injector) and Exhaust Gas Recirculation Sensor B Circuit High. Evaporative emissions systems test for knowing a leak in the fuel tank and related hoses. For the test, the computer pulls a vacuum and test to see if the vacuum holds.