96 2.5 obw 108k mi.

 

got in the car yesterday, and right on startup, the cel came on with p304, cylinder 4 misfire. new plugs and wires around march, new injector a couple months ago, and the cel seemed to go away for the most part (came on for half a day a while ago). Any ideas on where to go next?

timing belt, tstat, water pump were all replaced around 107k.

OEM Subaru spark plug wires or from the autoparts store? if it's not Subaru OEM then they need to be replaced again with Subaru or Magnecor wires only, these engines are not forgiving for cheap or low quality wires.

 

if they are Subaru wires then check to be sure the wire is seated tight and properly on the plug and coil pack. while you're doing that, make sure the wire isn't damaged in anyway.

 

in the end you can try to swap two spark plug wires and see if the cylinder misfire code moves with the wire. if you swap wires and then it gives you a "cyilnder 2 misfire" then you know the wire is bad for sure.

Blow it off as a Subaru idiosyncracy (sp?). If you've got a code reader, read the code then reset it. Otherwise you can throw money away at more plugs,wires,coil pack,igniter...you name it. My 97 Outback would throw a CEL at very nearly the exact same spot on a stretch of highway----didn't matter if the car was cold or had been run all day.

probabaly a hairline crack in the coil tower of the coil pack. Replace the wires first, but this is usually the begingings of a dying or damaged coil pack.

 

nipper

When I had a cyclinder #3 misfire it turned out to be the E.C.U. If you will get a cheap set of noid lights, check and see if it is getting a signal from the E.C.U. all you have to do is unplug the inj. and push the inj. plug on to the end of the light, if it is working it will flash.

96 2.5 obw 108k mi.

 

got in the car yesterday, and right on startup, the cel came on with p304, cylinder 4 misfire. new plugs and wires around march, new injector a couple months ago, and the cel seemed to go away for the most part (came on for half a day a while ago). Any ideas on where to go next?

timing belt, tstat, water pump were all replaced around 107k.

For that matter, a long heavy duty screwdriver (read 18" +) with the end of the handle pressed against your ear and the tip of the screwdriver pressed against the top of the injector cover will tell you if the injector is working or not. A lot quicker and you can listen for a difference between the injectors.

Seems like if you solved this before with new plugs, the correct ones woulda been installed, but here goes anyway. I had a cylinder misfire because the previous owner replaced the spark plugs with non platinum Boschs. NGKs only please. Or that other brand, whose name escapes me right now.

UPDATE:

 

AFAIK, the misfire has been fixed. The valves were cleaned during the headgasket job, and I haven't had a misfire since. Hopefully that gremlin has been exterminated.