When was the last time the engine was tuned up? No, not just plugs, but a full tune up! The whole nine yards! Any part of the secondary ignition will do this including the ignition coil or coils! This sounds like a classic ignition misfire! They usually go bad under a load like under acceleration, but can be noticeable at any time. It is very important to have your engine equipped with good tune up parts or you may be causing damage to other components of you car like the catalytic converter which can be expensive!
Ignition misfire causes by any bad tune up part and or ignition coil or coils.
Bad spark plugs, spark plug wires and cap and rotor (if equipped)
Wrong tune up parts spark plug, wires etc...
The quickest way to check the ignition components, is by looking closely for leaking secondary voltage. Visual look at all the tune up parts to see if you can see any sparks coming from any of the wires or coil (or coils) when the vehicle is running. If not, you can put your hand on the coil/coils and wires when the engine is running and see if you feel any small voltage leaking form the tune up parts. Check spark plug wires by connecting ohmmeter to ends of each wire in question. If meter reads over 30,000 ohms, replace wire(s).
ALso, with engine running, spray coils and plug wires with fine water mist to check for shorts. It will leak secondary ignition voltage from the tune up parts caused by high resistance from carbon tracking if they are bad. This is very common if the tune up parts are not changed regularly!
If any is found, the tune up parts are simple bad an will need to be replaced! If none is found than you can spray a mist of water on the tune up parts when the engine is running and see if that causes the engine to stumble or run rough at all. Again, if it does, the tune up parts are bad and will need to be replaced!
Here is some info about your code.
1. Using a Digital Volt Ohm Meter (DVOM), check the voltage on circuit 231 Tan/Black wire at the oil pressure switch with the switch plugged in and the engine running. The voltage should be near 12 volts.
2. If the voltage is low, unplug the connector at the oil pressure switch and again check the voltage on the Tan/Black wire.
3. If the voltage is still low, check the Tan/Black wire from the oil pressure switch to the Engine Control Module (ECM) connector C2 pin 37 for a short to ground.
4. If the voltage jumps up to near 12 volts with the oil pressure switch unplugged, check the oil pressure. The oil pressure switch should open at about 4.5 PSI.
Insufficient Oil Pressure
Oil Pressure Switch
Tips: Conditions for Setting the DTC P0520 The ECM detects that the Engine Oil Pressure (EOP) sensor signal circuit is pulled low. The above condition is present for greater than 5 seconds. When the oil pressure is above 4.5 PSI, the oil pressure switch opens, and the ECM senses a high signal voltage. The ECM monitors the oil pressure switch signal circuit and sends a class 2 message to the Instrument Panel Cluster (IPC) indicating the switch status. When the engine oil pressure is low, the engine oil pressure switch closes, the signal circuit is low, and DTC P0520 sets.
P0520 Engine Oil Pressure Switch Circuit Malfunction
EOP switch connector is damaged (check pins for damage, and moisture)
EOP switch signal circuit is shorted to ground
EOP switch has failed
ECM has failed