I have a 2005 4Runner w/ 4.7 V8 w/ 84k original miles. A few weeks ago the check engine light came on and the fault code came back as 0203 or 0303; I don't recall exactly but it was a "misfire on cylinder 3". In the past, when this has occurred on other vehicles, I have replaced the coil pack and the code clears. So, I replaced the coil pack and cleared the code; everything was fine but it came back again a couple days later. I should have realized that the truck still had the original plugs, and they were long overdue to be changed according to the maint schedule. So, I replaced them and cleared the code. The truck, again, was fine for a couple days but has now come back on again and I'm perplexed as to what it could be.
If it is fuel injector related, is there any way to check or clean an injector? Can I try running FI cleaner thru it? Any other ideas?
The day when it first happened, I noticed that when I started the truck, the battery/starter gave a momentary hesitation as it was being started. I thought it was odd and the code came up shortly thereafter. The battery was also original, so I figured I might as well replace it, too, b/c I noticed it getting weaker thru the winter months. But, I wondered if there could have been a momentary pulse or hesitation that could have screwed w/ the ECM that caused a false code....just fishing at this point.
Also, what is the best way to clear the code? I just disconnect the battery for a few seconds to reboot the system; it erases the trip meter, fuel mileage settings, and clock, but the radio stations are retained. Is there something else I should do to clear it? Again, just fishing.
If it is fuel injector related, is there any way to check or clean an injector? Can I try running FI cleaner thru it? Any other ideas?
The day when it first happened, I noticed that when I started the truck, the battery/starter gave a momentary hesitation as it was being started. I thought it was odd and the code came up shortly thereafter. The battery was also original, so I figured I might as well replace it, too, b/c I noticed it getting weaker thru the winter months. But, I wondered if there could have been a momentary pulse or hesitation that could have screwed w/ the ECM that caused a false code....just fishing at this point.
Also, what is the best way to clear the code? I just disconnect the battery for a few seconds to reboot the system; it erases the trip meter, fuel mileage settings, and clock, but the radio stations are retained. Is there something else I should do to clear it? Again, just fishing.