I recently picked up a 99 XJ8L that is running rough. The CEL is on and the car is in Restricted Performance mode. Here are the codes that I pulled and my understanding of them. Please let me know if I'm wrong:

P0306 - cyl 6 misfire
P1314 - misfire rate cat damage, bank 2
P1316 - injector circuit / JDM codes detected (excessive misfires?)
P0356 - injection coil F (cyl 6) malfunction
P1642 - restricted performance
P1000 - OBD2 scan / diagnostics not complete


Today I cleared the error codes and replaced what I thought was the cyl 6 ignition coil and spark plug (original plug did not look charred / oily). I started the car and just about a second or two later the restricted performance kicked in, and the car threw error codes P0356 and P1000 again, and its still running rough. If I kept the car running I suspect the other codes would be tripped eventually.

I thought cyl 6 is on the right side when facing the front of the car (US drivers side), third one back from the front of the car (numbered 2, 4, 6, 8 from the front). Is this correct? If I did in fact change cyl 6, do you have some ideas of anything else to look for to track this down? I am hoping I just screwed up and changed the wrong spark plug and coil.

Thanks

 

nevermind. I had the # wrong. I replaced 7 and not 6. I dug up a different diagram with the ODB2 cylinder #s overlayed and changed the coil and plug on 6. Car runs great now. I think the original owner changed 7 by mistake also and gave up. the coil on 7 looked brand new while the coil and boot on 6 looked sad.

 

This is from the XK8/XKR forum - same engine. It shows #6 second from front on right for your year.

https://www.jaguarforums.com/forum/x...esolved-78779/ - post #7.