Hi,

I have a 2002 Nissan Maxima with a 3.5 V6 engine. I am in the process of troubleshooting a P0300. By the way, I am not a mechanic.

I want to test my coil packs and I read on here that one way would be to start the car and pull each coil, one at a time, and see if the engine changes idle, etc. This make sense to me but my question is how do I do this test on the 3 coil packs in the rear of the engine. They cannot be accessed without removing the intake plenum (I think that's what it is called). This makes me think I can't test the 3 coil packs in the rear.

Is there another way? What should I do to test the 3 coil packs in the rear?

Thank you so much for your help!

you can test them with a multimeter, there are several youtube videos on how to do it

https://www.youtube.com/watch?v=SZPiD7nv9Bw

https://www.youtube.com/results?search_ ... axima+2000

If you are getting a random/multiple cylinder misfire code (p0300) but no supporting codes like p0301, p0302 etc, then most likely it is NOT your coil or spark plug or a specific injector. Instead, it would most likely be something that is associated with ALL cylinders like a intake manifold leak, mass air flow sensor, ecu, ground problem, etc.

Pulling the plug wire at the plug itself does the same test but has to be 6 separate coils, if 3 twin tower or output (waste spark) type then all you can check is pairs, not individual cylinders.

mac,one tip I giving for the "Idea" of multimeter testing (I don't know car & not condoning this strategy one way or another). Has to do with the peculiar aspect of ANY Hi-Voltage "situations" , always dangerous epecially if fooling with "Mains" sourced energy! Tip - a coil testing OK on ohms , continuity etc. IF there is ANY internal Hi-V potential for shorting , or worse the "intermittant shorting-internally" CAN BE A VERY FRUSTRATING situation you THINK you've cleared as OK - if your not aware of this scenario, one may go "nuts"& possibly never or after considerable time (wasted) realize that said Hi-Voltage device/ part/wiring whatever- IS Ok when not! This is what the term "burn-in" has to do with subjecting electronic equipment to ACTUAL WORKING CONDITIONS & SCENARIO . If coils are to be tested "hooked up & layed out" on top of manifold to SEE that a regular occuring spark , no "skipped beats", IS ACTUALLY SPARKING,one thing - you MUST ground the metal "frame" of the coil using jumper to manifold or block. That way you don't OPEN UP a "WAY" or "compromise" the insulation whereas a carbon-track can buildup and NOW YOU have created a fault to grow from intermittant short to all out "100% Dead Short" Also you NEED to put like a phillips screwdriver INTO the end of the "boot" all the way touching the "contact spring" inside, leaving a gap to block or manifold no more than 1/2" so spark doesn't also compromise the internal insulation.

OK. Thanks for the replies. I forgot to mention that besides P0300 I also got codes P0420 and P0442 and no other codes.

X2 post #4 but I would drop any testing gap to 1/4" or less, whatever the control device is there, spark module or internal PCM or ECM can be blown out trying to jump too wide a gap, the coil tries so hard to fire it goes to max load and kills the control device doing it.

Any coil on the planet can be manually tested by simply powering it up on the correct end and grounding the other and with a grounded plug lead in place simply ground and break the ground over and over, breaking the ground fires the coil.

Knowing the ohm spec is nice but be aware that the resistance can seem to be in spec and yet the coil still be bad, some of the numbers are so low in resistance that they can short and barely change the number. Also, it being a coil means you can have no short while tested and then short instantly in use to then test again as having no short. It's a coil, give it some thought, it jumps air to work. Making ohms testing worthless.

Sometimes the coils work, or don't when the engine is cool, warming up. As the engine get hotter the coil
might quit working. I think the Nissan Floor shop manual has a procedure for you to put the coil in the freezer .Ohm spec is a good first start but you still might not find the culprit that way exclusively. A coil swap you
mentioned first works best if the culprit coil is totally dead but if the problem is sporadic it is tough
to pinpoint. After checking the
ohm, ground wires, voltage from feed wires I will check the coil spark using a tester. I have used a Thexton part #458 NAPA# 700-2426 coil on spark plug tester i bought from NAPA auto parts. It has a clear glass tube so you can see the spark.
Be sure to write down all your readings for each coil.