Here's a description of my problem I have been having. I have a 95 maxima se, auto, that has been having random misfire problems with the check engine light the past 2 weeks. I searched on the thread and found and diagnosed the engine codes 0303 and 0701. Searching on the forum, I found Daniel B. Martin's suggestions for this code problem that he answered for another user.

Here's the thread:

http://forums.maxima.org/showthread....highlight=0701

Anyway, I never had problems with starting the car, as did the original poster of the thread did. Mine just started misfiring randomly, and got worse as time went on (I would have tried to diagnose it earlier, but my mechanic friend kept putting off looking at it, so I came to this forum to try to work on it myself).

This is what Daniel B. Martin wrote as one possible solution:


"You may test this "flooded engine" theory by cranking the engine with the gas pedal pressed all the way to the floor. Cranking with Wide Open Throttle is a signal to the Engine Control Module to "clear a flooded engine". If this technique gets the engine to run you will want to figure out why the engine got flooded in the first place. Possible causes of a flooded engine include
- fuel injectors which stick open
- bad fuel pressure regulator
- obstructed fuel return line

If you are lucky the Oxygen Sensor will recover spontaneously. If not you will have to remove the Oxygen Sensor and replace or rejuvenate it."

Well, I "cleared the flooded engine" by starting the car with the trottle wide open, reset the ecu code light, and test drove the car for about 15 minutes. The check engine light did not come back on, and I had no misfires, though, granted, I only drove it for only 15 minutes. My question refers to Daniel's statement about the OS recovering spontaneously. Does this mean that the problem is fixed, if the misfire does not reocurr, and the check engine does not reappear? Or, do I still have to test for the fuel injectors sticking open, a bad fuel pressure regulator, or an obstructed fuel return line?

Daniel Martin or anyone else who has a knowledgeable opinion on this would be greatly appreciated. Thank you.

 

Ok, here's some further update on the situation. I drove my car to work earlier today, and the check engine light flashed, then went steady on. After the light went steady on, I did not noticed any misfire in any of the cylinders. Just earlier tonight, as I was coming home from the bar, I noticed the check engine light disappeared, and things appeared ok, for now. Any ideas, anyone?

 

After working great for a month, my problem has resurfaced again. The check engine light came on the other day, and I have a misfire in one of the cylinders. Anyone have any ideas on how to further troubleshoot my problem to locate the source? Also, is it a bad idea to be driving around like this? Any help would be appreciated, thanx.

 

0303 = upstream o2 sensor.

0701 = multiple cylinder misfire

Change your spark plugs, use NGK Platinum plugs only and see if your problem continues. Make sure all the connections to your coil packs are clean and tight. You can spray some WD-40 on the electrical connections to keep contamination and moisture out.