02 ALTIMA, check engine light, multiple misfire



Hi to all.

My wifes 02 altima (4 cyl) has a reoccurring issue with check engine light coming on and the error code is multiple cylinders misfire

I have taken this car to the dealer 4 times and they of which they suggested 3x changing spark plugs and once they changed emission parts(o2 sensor also looks new). while changing spark plugs helps for a couple of weeks, the check engine light always comes back. I cannot afford changing spark plugs at110$ per hour rate.

I have changed them my self this time and code came back after 2 days.

my registration is due soon, so need it fixed.



What code number comes up? Just the number please, so one of our resident techs here can double check on it.

Check the plugs for fouling due to misfiring and then follow the leads (plug wires) back to the coils and test from there.
Perhaps there is a bad coil pack or there may be another ignition fault.


Thanks for a quick response.
I hate to say it but I dont have the number aviable, next time Ill make sure that Ill write it down and post them here.
I forgot to mention that dealer also claims that they cleaned fuel system, injectors, etc.
I think my next step will be a search for coils at a local junk yard( new ones are 100$ a piece and I need 4)
Ill be back with the error code


you do not need anything ,as of yet.

just post the code,and buy nothing.


will do


I got the code, it is:
P0302 - cylinder 2 misfire
Appreciate your help…


Only #2 cylinder misfire simplifies the problem, considerably.
Pull, and examine, #2 spark plug. If it looks ok, you can put it back.
Swap #2 ignition coil with another. Erase the DTC code (at an auto parts store, or get a code reader and erase it yourself). Drive the car for two, or more, “trips” to see if the check engine light comes on again. If it does, and the code has moved to the other cylinder, that shows the ignition coil as being faulty. If the code is still P0302, other checks will have to be done by a qualified independent mechanic.


this may be a stupid question. how do i figure out which cylinder is #2. they are placed horizontally. do I count from the left side? is there markings somewhere?


Not to complicate things but,our local Auto Zones will only read the code they will not clear them,is this situation the same in other parts of the country? wonder if it is a corporate Auto zone policy. I did read that some bussiness groups complained that Auto Zone was doing mechanical repair. I live in AZ.


i didnt even ask to clear the error codes. the way I do it I unplug the battery for a whole night and codes clear. if you unplug it for a short period it will not do. it might be different for other cars.
I also live in arizona :slight_smile:


WELL, no good news, I swapped coil #2 and #3, code showed up again and again misfire on cylinder #2. so coils seem to be ok.
I have purchased NGK spark plugs, also added fuel injector cleaner to my gas. Could it possibly be an injector on cyl #2?
Im loosing hope…


Yes, a fuel injector can cause a misfire. You could swap #2 fuel injector with another. Erase the code. Drive some “trips”. If the code moves with the fuel injector, that’s the guilty party. After this, it gets more complex. The repair manual will save you from stumbling around too much. Every part-time, and full-time, mechanic needs one.


Now, getting to fuel injectors seems like a tricky deal. Repair manual might be required. Im thinking that Ill drive it with the fuel injector cleaner for a day to see if it will change anything.
If it does I will know that the injectors are at fault.


OK now this is getting interesting. Since it wasin’t the plugs or the coils. Guy @ autozone recomended trying the fuel injector cleaner. 2 days later, engine still runs smooth and the “service engine soon” light still didnt come on. $5 fix, after all the money that I’ve spent on this problem, I hope it stays this way. Will see.
Thnx all


Glad you found a solution; AND, that you came back, here, with a resolution. We need the feedback, and the other readers need the feedback so that they can consider the treatment for their own vehicle problems.
A repair manual and an code reader are, still, waiting for you at the store. Someday, another problem may come along.


Thanx a big bunch


You’ve gone all the way from, “PLEASE HELP”, to, “thanx a big bunch”. Nice!


Add a fuel system cleaner with your next tank of gas and then add a few ounces of ATF to the gas tank with each fill up after that The problem is the injectors (old, maybe dirty), not the plugs or your sensors. The cleaner will get rid of any residue and the ATF will lubricate.


Have you had all recalls done because I had the ECM recall corrected and when that happened they screwed up the timing, and you are darn right that I had it corrected for free.