I have a 2000 4runner v6. I get codes p0300, p0301, p0302, and p0305. Which is misfire on cylinder 1,2 and 5. Starts to run rough then codes come seconds later. At first there was just 300 and 302 and then the other 2 cylinders come. Runs fine for first 10 minutes then it acts sluggish and cel are thrown. Car is still driveable when cel are thrown but it is a little sluggish. I was thinking it was possible bad gas, maf sensor, or fuel filter. Any educated thoughts please share what u think are possibilities.
misfure codes thrown after driving for ten minutes.
- Thread starter zedjr
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Can you give us any information on the history of the vehicle and what work has been done to it? For that many cylinders, the first thing that comes to mind is something fuel related, but based on it taking 10 minutes before misfiring, I'd lean towards an electrical issue. My guess is that as something electronic gets warmer it goes from operating fine to not. It could certainly be a fuel related component like the fuel pump, but if the plugs, plug wires, and ignition coils haven't been replaced in a while that's where I'd start my search.
There are 3 ignition coils. They are on the plugs on the passenger side of the engine, and the wires run from them to the drivers side plugs. Electronics can be sensitive to temperature, and be fine when cold, but go out of spec once they warm up. Having an ignition coil that is fine when cold and then doesn't work properly once the engine bay gets warm isn't super uncommon.
I assume you say it isn't plugs or wires because you have recently replaced them?
It isnt the wires or plugs cause all 3 went out at once or closely behind one another. It was just one on saturday and now 3. All happening when car is driven for ten minutes. Am thinking fuel filteror fuel pressure regulator or intake manifold leak but wouldn't this vehicle throw a cel for low fuel pressure and an intake leak. Am really just looking for other possibilities so i can start testing them one by one.
The ignition coils should be one of the easiest things to check. You can swap them around and see if the misfire follows the coil or stays with the cylinder. Minor hassle, and no wasted money on parts. The image below shows the coils and which cylinders they feed.
That reasoning is not enough to eliminate plugs or wires from your misfire problem. It makes them less likely, but does not mean they are good. Have you done any other work on the vehicle in the last few months? I would suspect cyl 2/5 coil pack is going bad and cylinder 1 is misfiring because it's having to pick up the slack (known as a sympathetic miss). LikeSkulking suggested try swapping coils around, but make sure you know the original and new location of the coils. I had a coil pack that tested within range when cold, but was out of spec once it warmed up.
spartacus
Senior Member
After making sure the plugs, wires and coils'are good. Your codes are all fuel related not electrical. Ohm out the injectors and see if they are within spec 13.8 at 68 degrees give or take a couple of ohms depending on temp. Get your injectors tested and rebuild or buy a remanufactured set of injectors.
DreadPirateJon
New member
Check your air filter, I was having weird misfires. And while looking into the air box the filter looked fine. A bunch of mud and dirt had gotten into the folds. Replaced the filter and they all went away.
