I have a 99 Galant 2.4L. I was wondering if a leaking spark plug tube seal could cause a cylinder misfire when the engine is cold. I am finding oil around top of plug wire and base of spark plug. Service engine soon light is on and the only code is P0301 cylinder 1 misfire. Wires and plug are both new. Only misses when cold, runs fine when warmed up. Any help would be great.

 

Yes it can, because it causes the wires to fail. Did you change the boots under the coils when you changed the wires? If not you need to. With the miss fire code you need to replace your valve cover gasket and tube seals then put in new plugs, wires, and boots.

MD310913 VALVE COVER GASKET $16.27
MD198128 TUBE SEALS $ 9.85 EA. (4)
MS851357 SPARK PLUGS $ 3.60 EA. (4)
MD338624 CABLE SET $68.88
MN158977 COIL BOOT $17.68 EA. (2)

 

I did not change the boots, didn't know I could. Still learning about this car, really love it though. I had changed the plugs and wires(not the boots) and it ran great for a week, then started the misfire when cold, not sure why just when cold though. Sounds like you might be on to my problem. The part #s & prices are they dealer?

 

YES

 

Well, I have replaced the valve cover gasket, tube seals, coil boots, plug wires and plugs. I am still getting the same hesitation when the engine is cold and the same error code, cylinder 1 misfire. Any ideas or help would begreatly appreciated.

 

I don't know. 9 out of 10 times it's a plug wire or boot.

 

I learned a lesson on this one. Don't assume new parts are good. Found out the "new" spark plug in #1 cyclinder was bad. 1st swapped the coil packs to see if misfire would follow, it didn't. Then swapped plugs and misfire followed. Replaced the "new" plug with another new, has been running great for almost a month now. Frustrating lesson learned!