alrighty...
major gremlins addressed, now on to the comfort and fun ones...

Scoured the threads so far, but am lost a bit, on the radio, I can insert a Cd, eject it fine, however, there is no sound playing at all. The display shows the track number and all, no errors... I unplugged the amp, and have no sound at all. the weird: as I adjust volume, I hear popping in the speakers as I go up and down on the CD changer only. Premium Alpine sound car..The other options, everything is perfectly normal. Thoughts on this one? I assume that since I lose all volume by unplugging the amp, the amp should be good? is there a audio connection I am missing? probably need to pull the head unit out, but I don't have a radio code for it....yikes!

2ndly, my xj8 smokes the crap out of my xk8.. same engine, transmission, but at 1/2 to 3/4 throttle, the xk stumbles and picks up speed slowly, no codes. if I smash the pedal, it screams like it should! However, my xj8, at 1/2 throttle, it kicks down and screams like a bat out of hell! What am I missing here? Since its an 03, its DBW, so no cable to adjust correct? I know the cars are 5 years apart, It may be a ECM reprogramming issue, or something mechanical I'm missing?

 

Look up throttle cable adjustment on this site. It can slip.

 

even on an 03? I thought the cable adjustment was for the 4.0 engines, not the 4.2?

 

The throttle cable adjustment applies to the 4.2 as well. It brought my wife's 2006 XK8 back to full power a few years ago....