1998 engine misfire code

I have a 1998 Legacy Outback, 2.5 engine/MT, with 104,000 miles. About two summers ago started getting misfire code (flash a few times, then stay on solid for one to five days before going out). It would move around to different cylinders, but always two cylinders (not always on the same side of the engine). Last summer thru now it has stayed 1 and 3 cylinders. Coming and going about 6 times a summer, but never in the winter, until now (12/26). Changed in this order: spark plug wires, spark plugs, coil pack, all fuel injectors, camshaft and crankshaft sensors. Have run 44K thru fuel a couple of times. I never have felt a miss in the engine. Idles ok, slight hesitation when cold. Owners manual says to have the valves adjusted at 100K have not done. My independent Subaru mechanic says its probably a computer glitch, not to worry. Second opinion independent Subaru mechanic by just listening to the symptoms guarantees me that its the head gaskets and the heads need to be redone ($2000). I would like to get rid of this issue, but tired of spending money without results. Help!!!!!!!!!!!!

I would not be surprised if it was a headgasket issue. The 2.5L engines had bad headgaskets around the year and milage of your car.

Try getting a compression test done. that will tell you if you have a bad HG. Also, if theres coolant in your oil, or oil in your coolant, or bubbles coming out of the coolant resevoir then thats a sure sign as well.

If its a computer glitch, you can always try resetting the computer. Just disconnect the battery for a little while.