hello.

i have a 99 Maxima with 80,000 miles that has a misfire at idle. there
are no codes showing up and i checked the coils. i haven't checked the
injectors yet, but will do that soon. if i put a can of the good fuel
injector cleaner into the tank the misfire is gone. so i am wondering
if there is something wrong with the injectors or the coils. does
anyone know if it could be the injectors or the coils that might be
causing the misfire? has anyone had any experience with a misfire
disappearing when using fuel injector cleaner? any help will be
appreciated.

What do you mean when you say you "checked the coils"?

If the car is misfiring at idle, you can disconnect one coil at a time.
When you get to the cylinder that is misfiring, disconnecting the coil
will have no effect on how the engine runs... that will help you
pinpoint the bad coil/injector/plug.

As an aside, you have a 99 Maxima. That model year is prone to
iginition coil failure, so I'd bet that bad coil(s) are your problem.
The only fix is to replace all 6, because they will all fail
eventually.

You can buy coils online at a discount from pinnacle nissan, courtesy
nissan, jerry rome nissan, etc.

I assume all the other maintenance is up to date (plugs, filters,
etc.).

Cheers,
Nirav

In my 99 Maxima with 72k, I have similar misfire even after replacing one
coil from CEL code. Many have solved this problem by replacing MAF sensor
which is what I expect I'll have to do. Does anyone know if there is a
diagnostic protocol? It seems the dealers want to replace coils and O2
sensors before they look at the MAF sensor.

<inag99 (AT) netzero (DOT) net> wrote

As already mentioned, you have to replace all 6 coils.. it's unlikely
that your MAF is causing misfires (if that's the CEL code you are
seeing).

Nirav

i am well aware of the coil problems in the 99 max. my main question
was why is the misfire gone when i use injector cleaner in the tank. i
am getting no CEL codes at all.