dallascharger

P0301 Misfire #1 Cylinder
P1607 PCM Internal Circuit Failure
P0302 Misfire #2 Cylinder
P0303 Misfire #3 Cylinder
P0304 Misfire #4 Cylinder
P0306 Misfire #6 Cylinder
P0300 Random Misfire
P1399 Misfire Inrse Any Cylinder

Hello everyone, noob here begging for any words of wisdom. The suggested course of action is to replace coils and plugs. So I have ordered the NGK Platinum plugs and the NGK coils. Is that going to clear the PCM error code or should I be starting with that?

justnspace

iTrader: (1)

suggested course of action is to troubleshoot, instead of replacing all plugs..

it could very well be just one cylinder that needs attention. or it could very well mean that your head(s) (specifically the valves) are fucked.

Iggy

It won't be the plugs. Go after the P1607 first. Could be something as simple as a bad ground.

justnspace

iTrader: (1)

Good call.

I would disconnect the battery for a few seconds to a minute to clear codes...

then wait till codes come back up

dallascharger

I took justnspace advice and started troubleshooting the coils and plugs, found a bad coil and replaced, but as I also replaced the plug I found the actual source of the misfire was possibly a bad gasket since the plug was covered in oil along with coil.so now I have to dig deeper, anyone have experience with this issue

Iggy

Pretty common. Each spark plug tube has a gasket in the valve cover and with time the gaskets get hard and brittle. The only fix I know of is to pull the the cover and replace the gaskets. They sell kits which include plug tubes, bolts and main cover gaskets. Don't cheap out on the gaskets because you don't want to do the job more than once. It's a pain the the ass.

When oil pools on the outside of the plug it creates an electrical path to ground, essentially shorting out the plug before the energy gets to the electrode, which leads to early coil failure..... Could be that was the cause of your P1607. Keep an eye on it.

dallascharger

Ok thanks, going to Autozone for kit now, and see how it goes. Hopefully this will clear my CEL

Iggy

A quick way to clear any codes in the ECU(engine computer) is to pull fuse #13(clock/backup) on the interior passenger side fuse box for about a minute then reinsert.