# 02 Altima P0303 ?



## Pooch (Sep 7, 2014)

I just got a 02 Altima 2.5 SL with 44,300 miles on it and that code keeps popping up. This didn't happen when I test drove the car(private sale) I have read several other threads about this and the intake gasket leaking. Is there any other fixes for this? Also getting P1612, 1614, 1615 errors. Any suggestions? Thanks in advance


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## rogoman (Dec 16, 2004)

The P0303 code means that there's a misfire condition in cylinder #3. Here are the possibilities:

- Dirty spark plug
- Improper spark plug
- Insufficient compression
- Incorrect fuel pressure
- The injector circuit is open or shorted
- Fuel injector dirty
- Intake air leak

The P1612, P1614 and P1615 codes deal with the NATS (Nissan anti-theft system). Did you have your keys replaced?


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## Pooch (Sep 7, 2014)

I think maybe the keys were replaced before I bought the car, story is they took it away from the guy's 95 yr. old mom. Only got 1 key. Will I have to go to the dealer to get more made? Is the intake air leak a known problem, any recalls or anything on it?


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## rogoman (Dec 16, 2004)

To get more keys made, you can buy blank keys and FOBs from Amazon or Ebay cheaper then from a Nissan dealer. Once you buy a blank key/FOB, take ALL the keys to a Nissan dealer for re-programming them.

To check the intake system for a vacuum leak, attach a vacuum gauge to a full vacuum source. With the engine fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be 21 InHg.

If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. The gasket may have failed; spray a water mist at the gasket to see if the gauge reading changes. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.


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