Ok guys, l started having problems with my car a few days ago, I changed the spark plugs(NGK) three weeks ago, I dindnt changed the ignition coils, car ran fine till last week after I seafoamed, it started to shake and run like s**t.........No I have a P0300(random misfire) and P0301(misfire on cylinder 1) any ideas?....could be the ignition coils?...or the injectors?.....BTW I drive an 08 with 63000 miles......Mods done on the last couple of weeks, BOP plate, grounding kit, HIDs 6000k.......any ideas?......Thanks in advace guys.....

 

My friend changed my plugs for me few weeks ago. When I started the car it was shaking a lot and when I started to drive it was shaking as well and check engine light started to blink and then stayed on. I got misfire on cylinder 4.
In my case it was just a bad connection on the coil connector, my friend didn't clicked it all the way. And lucky me cylinder 4 is the middle one on the front bank.
You can have something as trivial as that. Good luck.

 

I recommend that you swap coil packs from 1 to 2 and see if the problem moves with the coil pack. While you are doing that, I recommend you pull the spark plug and check it. Clean it good. You can check if the coil pack is good by connecting the coil pack with the sparkplug and placing the spark plug thread on the block while someone turns it over. If you don't see a spark, that means the coil pack is broke. $71 from Orilley's Autoparts each.