P0300 Random Misfire for 2007 Jeep Grand Cherokee?

[ihab_mo]

Hello I have a random misfire for a 2007 Jeep Grand Cherokee and I have already changed the spark plugs, coil packs, and fuel injectors. I was told it may be an electric issue due to a computer issue. Also I have to mention that I have a smaller battery in my car (500 cold cranking amps & 625 cranking amps). I believe that the misfire issue is still happening because I don't have the correct battery (my Jeep usually has a bigger battery that has 900+ cranking amps) for my car but my mechanic has been saying that the size of the battery does not matter. I would appreciate your input, Thank You.