I recently got the code P1320 (anyone know what this means? It's not in my scanner's manual for generic error codes). Today, I pulled out all of my ignition coils, cleaned them off, and reinserted them. I noticed an instant increase in performance, but now the engine makes a slight hissing sound every time I press the accelerator. Plus, it is now giving the error code P0174. Could this mean I need a replacement MAF sensor? I recently tried cleaning it with MAF cleaner, but that doesn't seem to have helped... maybe I even damaged it somehow?

Also, does anyone know what kind of tool to use to unscrew the screws for the MAF sensor? They appear to be a star-shape with a hole in the middle.

 

You can a set at autozone for roughly $10.

 

P1320 is "Ignition Signal". From the FSM:

Malfunction is detected when the ignition signal in the primary circuit is not sent to ECM during engine cranking or running.

Possible Causes
* Harness or connectors (The ignition primary circuit is open or shorted.)
* Power transistor unit built into ignition coil
* Condenser
* Crankshaft position sensor (REF)
* Crankshaft position sensor (REF) circuit

The P0174 is "FUEL INJECTION SYSTEM FUNCTION (LEAN) LEFT BANK".

Possible Causes:
* Intake air leaks
* Front heated oxygen sensor
* Injectors
* Exhaust gas leaks
* Incorrect fuel pressure
* Lack of fuel
* Mass air flow sensor

The left bank of the engine is the one by the radiator. The fact that you hear a hissing sound makes me think you have a vacuum hose disconnected.

The screws on the maf are Torx and the hole in the center is for security, so you need the Torx Security set. IIRC the maf screws are size T15.


If you need a FSM, you can download one from here:

http://boredmder.com/FSMs/Nissan/Maxima/

 

Thank you! I will certainly have another look tomorrow, especially for the origin of the hissing sound.