Skip the auto shop - Our mechanics make house calls

Q: I have a 1997 nissan maxima that has a misfire code of p0300 and p0302.

asked by on

I checked the coil packs and harness connector with a multi-meter and all are getting a reading. I also started the car and took off each fuel injector connector and every cylinder gives a drop in rpm. I removed all the spark plugs and noticed that cylinder #2 is wet with unburnt fuel and all the others are dry. The car was sitting for about 3 weeks and I barely started to drive it. What could be my problem? Car is running rough and shaking at a complete stop. Should I waste my money on fuel injector cleaner and spray out the throttle body with cleaner to see if it helps any? Before I did any of the work I mentioned above, I replaced cylinder #3 coil pack because it was too short and it was arcing, but now its misfiring on #2. Please help.

My car has 243500 miles.
My car has a manual transmission.

It’s common to find the source of a misfire in the ignition system. Checking the coils with an Ohmmeter doesn’t really tell you much though. When I diagnose a misfire, sometimes I find it helpful to swap the coils and plugs to another cylinder and check to see if the misfire codes move. That way you can isolate the fault without buying a bunch of parts that you don’t need. But if you had a coil that was arcing, it’s possible there has been some damage to the ignition primary, and you will need a scope to diagnose that. I don’t really recommend the Fuel injector cleaner. It’s a good maintenance procedure, but I’ve never actually cured a misfire with it. If you want help sorting this out, you can contact Your Mechanic to have a technician come out to your home or office to check out you misfire and recommend a solution.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • I have a 1997 nissan maxima that has a misfire code of p0300 and p0302.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Was driving down rd, car just quit. New fuel pump on just turns over but wont start except with ether 2005 Nissan Maxima

Hello - your success with spraying ether (and starting) is telling. The fuel system has failed. Check the fuel pump fuse(s) and the fuel pump relay. Either of these will keep the pump from running properly. I recommend a fuel...

Q: How do I remove heater core in a 1994 nissan pickup

Hello, thank you for writing in. The heater core is a difficult component to get to. Typically, you must go through a lengthy process of accessing the core from behind the dash. Once you have access to it, you can...

Q: Van dying when put in gear

I think the most likely cause would be a faulty computer or sensor of some kind. I would recommend having an inspection of the engine and transmission performed by a professional. It would also help to scan the vehicle...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...