For about the past week i keep getting a random missfire code poping up. I can fell the car sputtering under light acceleration, but it seems to clear up under heavy acceleration. I checked my spark plugs, and they were fine. 3 of the were alittle loose so i tighten them down, i also clean the intake manifold and it's still doing the samething. One of my coil packs was soaked in oil b/c one of gaskets around the spark plug cylinder was busted, but i'm not sure if thats the problem. Can anyone help me out?

 

Are any other lights on besides Check engine?

 

nope, CEL is the only light on

 

I had that code and it turned out to be a bad coil pack, which one? I don't know as I got a deal from Steven88 on a complete set of working used one's problem gone. The oil in the plug ( which I've had before also) shouldn't caause the random missfire if anything it would be a cylinder specific code.

 

probably a bad coil. Take it to Redline and have them pull the code instead of autozone. Redline has a much better code reader that can tell which cylinder is misfiring. Autozone's reader just tells you that one of them is bad, not which one.

 

Actually it may not , after using my OBDII scanner and only getting the P0300 ( random miss fire ) I took it to my mechanic who has a mega machine thinking it would isolate the coil, but nada. There are various ways to isolate it. Here's one way: http://forums.maxima.org/showthread.php?t=451830

 

you're right: could also be a fouled plug (checked) or bad connection. Regardless, he needs to get it checked by a reader that will tell him which cylinder is misfiring.

 

I'm experiencing the exact same symptoms. jay-pee, what'd you end up fixing? I'm trying to decide if it's my MAF or a bad coil - I suspect it's a bad coil. I've gotten multiple p0300 codes, but I have gotten a code for a misfire in cylinder 6 once.

 

Bump hoping for a response from jaypee/others. Also, an easy way to test for a bad coil if you're getting a SEL for a particular cylinder is to just swap the coil to a different cylinder. If the code changes to the swapped cylinder, obviously the coil is bad.

 

Ended up being a bad maf when mine did this. It was light sputtering on light loads and fine under wot. Then one day it completely fell on its face.

 

i got a random misfire once or twice. cleared it and they never come back.

 

I envy people that have specific codes onto which cylinder was misfiring. Mine wont misfire for more than 10 seconds and i don't feel like changing all the coils (money issue). I've tried the resistance test, but didn't have a DVOM with 20ohm option. :sigh:

 

if there is oil on the coil packs that could be the problem--if the coil has oil on it the spark could be getting lost through the oil--electricity travels the least path of resistance and oil would be the least path, so the spark would get lost and that cylinder would misfire--now to have a random misfire code there are 7 possibilities p0300-p0306. and if you have a multicylinder misfire code-if you haven't replaced your coils you should otherwise I would run a power balance test to see which cylinder(s) are misfiring and check them out but most people dont have access to the consult 2 unless you work at the dealer

 

im having a similar problem i keep getting cylinder 2 misfire and i thought the studder in low rpms was because of the fuel cut issue also my CEL blinks sometimes usually whn i go over about 3200 and then stops and does it again ... wat do i need to get raplaced?

 

oh and i replaced all my sparkplugs but it still happens

 

why don't you just fix that oil leak and watch the car for a while. You need to replace spark plug tube seal, you can get them together with valve cover gaskets and do the whole thing since you will be removing the rocker cover to get these tube seals in.

 

Pull your cylinder 2 plug and inspect it. Also inspect the porceline for hairline cracks. Replace the plug and switch coil #2 with coil #4 or 6. If the problem goes away it was your plug. If you start getting p0304 or p0306 then your coil is bad. Also if you are getting any primary ignition system codes (p1420 IIRC) then it's not likely a plug issue, most likely a coil.

 

If you are getting a misire and your checked or replaced the spark plugs & the coils the next thing you should look into is having engine compressions done. Reason why I am saying this is because I have same problem on my 3.5 QX4 where I am getting 0303 cylinder 3 misfire. I had compressions done yesterday, and I am in trouble. The range where cylinder comression should be on 3.5 QX4 is 130-168 psi, on cylinder 3 I am not even hitting 90 psi. In this case to solve the problem you'll be looking at 20 hours of labor to replace the rings or shopping for a new engine.

Andrei

 

Sorry for the late response, not really on here that much anymore. I'm not exactly sure but if this was the problem but, my back valve cover was leaking oil into one of the spark plug cylinders. After i changed the valve cover the problem went away. By the way, oil had been leaking into that cylinder for over a year.

 

well i just got the generic P0300 Multiple Cylinder Misfire

funny thing, the car is driving fine. i reset the code and i will see if it comes back. if it does, im going to start with the plugs since im pretty sure they have never been replaced.

pretty sure my oil burning engine messed the plugs up.

 

just found this about the P0300 that doesnt tell you a cylinder...interesting.

Random misfires that jump around from one cylinder to another also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

 

I had a misfire code (P1420?) around New Years, with the wonderful CEL. The car was running OK except for slightly difficult starts when the engine was hot.

A couple of weeks ago the CEL decided it had had enough and turned off. Still giving the slightly difficult starts but other than that, no problems. (and no new coil packs!)

Before Christmas I did have the MAF replaced and the computer updated due to the updated MAF specification.

 

Good that you got the problem fixed .

But to anyone with the problem..

Does the car have trouble starting up? Like when you crank, it doesnt start sometimes? If so I would say it was a coil pack. When it happened to me it was a bad coil and a bad plug.

Does the the car shift smooth in all gears? Like do the rpms hang a little when the gear changes? IF it hangs id say it were a MAF problem

 

Sorry for waking this thread from the dead. But I am looking at a 1998 GXE and it has the P0300 code which says it's a random misfire. The FSM says it could be a lot of problems, not just coil pack(s).

I'm contemplating on purchasing this car and using it for my daily driver, that is, if I can repair it.

The car does have trouble starting up (as Outmaxxed stated above). The car runs terribly rich.

Stan

 

Yea, I'm getting a slight misfire at idle also ill just change my plugs and see what happens

 

I have a P0300 and a bad misfire car sounds sick change coils and plugs can anyone help..

Thanks

 

any o2 sensor codes?

 

bank 1 sensor 1 low heater circuit

 

I had the same problem at one point it was a random misfire then specific cylinders ended up replacing some coils and plugs. still didnt fix the problem then i found a TSB where a wire in the wiring harness that wraps around the right corner of the motor was broke which was causing the engine to misfire. you can always try wiggling that harness on the right side(passenger side).

 

thanks

 

I had CEL for misfire change the all the spark plugs. Still didn't do anything. Finally I had to spend some real money got the COILS changed and now no more misfire. Loving the the dashboard without CEL.

 

did that already

 

Can sombody help bad missfire changed coils and plugs and the only other code was an O2 sensor bank 1 sensor 1 low heater circuit. Car starts but even at idle it sputters.

 

My 99 is sputtering at light acceleration or when trying to accelerate in passing. My CEL has not come on, I have replaced coils in the passed and it feels like something like that. I am going to change the spark plugs first with Autolite Platnums. Hoping to see if I can notice any coils that don't look quite right. From everything I have read, I seem to be going down the right path. Engine Coils are the only things I have ever had issue with on this car.

 

im having the same issue but i have a o2 sensor rear bank under threashold, i spray throatle body cleaner in the hoses and it goes away after a minute im gunna get some seafoam today ill let you know how it works out


ps. this happens about once a week?