I have a 2009 Mazda CX-7 with a history of ignition coils needing replaced. I was blaming it on O’Rielly cuz their parts are junk. Any way the code p0300 random misfire and p0113 (I think that’s the oxygen sensor) but then another code p0304 came up as a pending code. But if I change ignition coil on cylinder 4 will that fix the random misfire code maybe. I have four new ignition coils that are a different brand. Spark plugs have only been in there a couple months. 2 of the ignition coils were new 2 months ago also.   Or should I just change all 4 of them? And do those problems affect the 02 sensor code that also came up. I know some problems affect other parts. Anyway hope this makes a little sense.