The plugs and wires were replaced in September.....less than 500 miles of driving on them....

 

#6 is a common one for misfires.
By the way, it is the 3rd. plug back on the passengers side.

 

Thanks...I will let the mechanic who hates Land Rovers know. He also hates volvos, benzes and beamers. Welcome the Eastern Shore of Maryland!

 

Using any other plug wires than the Magnecors will cause mis fires in a very small amount of time.
Have your guy replace the plug wires that he installed and give you a refund for the cheap plug wires and have him install the Magnecors.
You buy them from Tony Cerrones and then have your guy install your plug wires.