I have a '99 Disco II which had the plug wire changed about 1.5 yrs ago and the plugs changed 5 months ago. Just recently the engine began running rough at 1k-2k RPM and seem to smooth out at higher RPM and acceleration. Then the CEL Light came on. Used and OBD II scanner and pulled these 3 codes. P0306, P0307, and P1300 (misfire 6, 7 and Manf. Control ignition system or misfire). Pulled the plugs on 6 and 7 and replaced them because the were super carboned upped (if that's a real sentence). Should I be looking for something else that caused it or just righ it off as the 2 plugs going bad in 5 mos?

 

Most likely, your exhaust valves are sticking and causing the light.

 

Had this problem a few years ago on my 99 disco II... Cylinder 5 misfire. Car would shake violently when I accelerated, and then the CEL would came on. Rover pulled the code, and found it was bad ignition wires fouling out and arcing to the engine block. Rover dealer wanted $600 to replace the wires (what?) so I found a parts dealer in Kentucky, bought the wires for $49 and did the work myself. Since then, no problems.

Also had a problem with Mass Air Flow sensor (once) but nothing since then. Sounds like your problem is ignition or exhast related. Hope this helps.

 

Were the codes for misfire or were they specific to the ignition cables....Thanks!

 

Code was for the cylinder - cylinder 5 misfire, specifically. But thanks to that code, we traced the problem to the wires. You could actually see the sparks jumping from the wire to the engine block.