之前的帖子

Background:  About a year ago I replaced the 4 spark plugs for my 2012 Subaru Legacy. It took me a while to unscrew the old spark plugs and took them out but when I tightened the new spark plugs pretty soon I felt it was already tight and I did not go any further because I did not want to overtighten them.  Several days alter my check engine light was on and the code was P0301 Misfire Dected in #1 Cylinder. I tried to tighten the spark plug again but it was still pretty tight so I just erased the code and the car was running fine for about a year.

recently the code P0301 came back again and if I erased it the check engine light will turn on again the next day. Now what can I do? I can bring the car to a dealership but just feel it is stupid if the problem is the spark plug is not tighten enough. Should I just try unscrewing the spark plug and tightening it again and see how it goes?  Or should i just let a mechanic to handle it?

原来的帖子快沉了，发一个新的继续，

按着坛子里有几位建议先挪了一下1和3的coil, 之后一天CEL灯都没亮，本来心中还期盼这样问题就解决了，回到家一扫描p0301 pending. 这下应该可以确定不是coil的问题吧？下一步是不是交换spark plug再看看？如果是spark plug 1的问题直接换还是买个spark plug gap tool量一下先？这几个spark plug都是大概一年前一起换的。