Guys & Gals,
Long time reader of this forum, but firstime poster.

Thank you in advance for assisting me through the process. What I have in a 1999 XK8. Yesterday at startup, the engine ran normal for about 5 seconds then begun misfiring. The reduced performance light came on including the check engine light. I shut off the car and restarted it with the same results. The issue is interment. I drove it around the block and one minute its fine then back to misfiring. The following codes were observed.
P0302 – Misfire Detected, cyl 3
P1313 – Misfire Rate catalyst damage, right-hand bank.
P1316 – Misfire excess emission
P0352 - Ignition coil primary/secondary circuit malfunction, cyl 3
P0353 - Ignition coil primary/secondary circuit malfunction, cyl 5
P0355 - Ignition coil primary/secondary circuit malfunction, cyl 2

Thoughts? ECM? Other Censor?

Secondary question, was the two Ignition Modules (Denso LJA1450AF) from the AJ26 eliminated and added the ECM on the AJ27?

Disconnect the coil pack for B4 (cylinder #8) or;

Swop the B4 coil across to the same position on the other bank.


Clear the codes, restart the motor and then re-read codes
Post back what you see.


Yes.

Not likely to be the "ECM"

I'm getting different data re your codes.
0352-A2, 0353-A3,0355-B1 (this may just be alternate cylinder numbering though)
but regardless l think you should have AJ27 so coil modules are built into each coil.
I did have similar problem a few years ago when one coil failed due to feedback circuit short to ground, that will cause a misfire on all 4 cylinders in that group. One new coil fixed it.

Thanks for the feedback. I should have the car back in my garage within the next few days. I'll post what I find.