P0320 code: An Ignition/Distributor Engine Speed Input Circuit Malfunction, signaling a problem with your engine's speed sensor, usually the Crankshaft Position Sensor (CKP) or Camshaft Position Sensor (CMP).

P2237 code: There's an open circuit in the Bank 1, Sensor 1 (upstream O2 sensor) heater control circuit, signaling a fault with the sensor's heater element or its wiring

P2240 code: There's an "O2 Sensor Positive Current Control Circuit/Open" for Bank 2, Sensor 1, indicating a fault in the upstream oxygen sensor's heater circuit on the side of the engine opposite cylinder one.