wiscoutback

Thanks for the responses. CEL came on again today - codes 301 -306 again. I can't find the pictures I took of the old plugs, but nothing too crazy there as I recall. A little dark residue from sparks, all looked the same. If I'm feeling spunky tomorrow I'll remove the plugs and take a look again. I'm going to do the seafoam treatment into the intake, unless there's any reason I shouldn't... Maybe this will clean off some of the carbon deposits. I'm hoping for low cost solutions that I can do myself! I've never checked for compression, injector signature or resistance testing, cylinder contribution test, a-f ratio test, etc. before, but I'm willing to do some work if it will help me diagnose the problem. Any suggestions on cheap and easy ways to do this, I'm all ears. I'm pretty handy and willing to do some work, but I just don't have the garage setup to drop the engine and start rebuilding the cylinder head assembly... One thing I forgot to mention but might be relevant - The engine has been using up oil internally at the rate of about 1 quart per 1000 miles or so. No external leaks. Could this be related?

I used the recommended plugs straight from Subaru since I was told it makes a difference with these engines. The check engine light was coming on before the spark plug change out. I don't think it was a flood car... nothing in the carfax about it.

No rust or corrosion under the hood. Good suggestions though. Gives me a few more options to investigate.

Very little oil noticed in the tubes and the spark plugs looked like they needed to be replaced, but nothing out of the ordinary. Everything went back together as it was. Sine this is a reoccurring issue I'm not quite ready to suspect the gas...

Hoping some friendly and knowledgeable folks out there can help me. I have a 2012 Outback with a 3.6 liter H6 engine and the check engine light is on. I drove it to an auto parts store to read the code and it came back as all six cylinders misfiring! A little history here - I purchased the car used from a dealership in Florida one year ago with 70,000 miles on it. While driving it down to WI, I noticed a brief, but fast vibration coming from the engine between 3rd and 4th gear, usually when the car was under load. The engine would also hesitate when accelerating, especially up hills, but usually only did this when it was cold. I had it checked by a Subaru dealer and they thought MAYBE it was a failing torque converter? and gave me a pretty high estimate for shop costs on a hunch. I did some research online and decided to replace plugs, tube seals, and valve cover gaskets and have the fuel injection system cleaned. It took care of the problem for a few weeks, but now the problems are back and bad as ever. When the CEL came on, I was expecting to see a code for one cylinder misfiring, but it came back with a misfire code for all 6. Makes me think it's not the ignition coils, but something potentially worse... I would REALLY appreciate advice on ways to diagnose this issue. I really like this car and can't afford a new one!