Jump to content
Ultimate Subaru Message Board

Check Engine Light - P0302 P0304


Recommended Posts

I have a 2001 Forester with almost 60,000 miles and the car has recently become very jerky at times. The check engine light flashes and then goes solid. The codes stored are P0302, cylinder 2 misfire, and P0304, Cylinder 4 misfire. Initially, the jerkyness would only be for a minute when the car was first running during wet weather, now it seems to never go away during any type of weather. When the car was running rough, I popped the hood but didn't see any sparking from any of the wires. I sprayed a fine mist of water on where the spark plug wires connect to the coil and I saw a lot of sparking on the cylinder 2 and 4 wires. It was right at the junction of the spark plug wires and the coil. Is this likely bad wires or a bad coil? Any other ideas?

Link to comment
Share on other sites

Well at least replace the wires and see if it goes away or just replace the wires and coil. If you don't have money for the coil I'd clean it off good and coat it with silicone spray and maybe wrap electrical tape around where you saw the sparks. Best to put silicone dieletric grease inside all the boots. Typically OE wires seem to be spec'd on this board though many also use aftermarket wires.

Link to comment
Share on other sites

Dug,

 

You should consider yourself lucky! This is a rare example of having a clear reason for having those misfire codes being set.

 

Examine/clean the contacts in the coil where the wires plug in and if those connections appear clean/good and you still have the misfire and spark jumping replace your spark plug wires. The wisdom on this forum will advise you strongly to use only genuine Subaru original equipment wires.

 

Let us know of your progress!

 

Cheers,

Mike V

Link to comment
Share on other sites

I would look closely at the coil. These are prone to cracking and then acting just as you described when damp.

 

Wires are cheaper however and are not a bad 1st suspect. If they don't clear up the misfire, then get a new coil. I would get a Subaru coil only however. Did have a tough to find problem once with a coil that had no markings on it and I was certain was not a factory part. Same with the wires.

Link to comment
Share on other sites

I've had this happen to my two OBW (96 & 99). Replaced plugs & wires... all is well. The '96 has a tendancy to through those codes periodically (every 3 - 6 months) I clear the CEL & drive on. Seems to be "very" sensitive to the smallest fluctuations.

Later,

Peter:cool:

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...