My 03 XJ8 has developed a rough idle and a bit of a ticking sound at start up. Should I be able to use my Actron CP9125 code reader to figure out the problem? I'm basically clueless beyond plugging it in and scrolling through the codes. Any real basic primers out there? I've search youtube to no avail.

 

Plug it in and post any codes - don't worry about P1111 which just means the diagnostic cycle is complete.

 

Let's see the codes before we start guessing!

 

What do you mean by "rough" idle? Does it feel like side shaking... like there is a couple having sex on the backseat while you're waiting at the traffic light? If yes - I had the same problem and the reason for this is air leak... in my case I'm still trying to fix it... also some times at cold start it needs a little push on the acceleration to gain normal RPM, because after the start-up it's holding something around 450-500 and the engine feels unstable... if I step just a little bit on the acceleration everything seems to enter in normal working condition

 

I wasn't clear with my 1st post, sorry. I'm really looking for instructions on how to use my code scanner. I'm using my iPhone right now so let me post a better explanation later. Sorry for the badly worded post.