I have 07 G35 Coupe base, recently my cats went bad affected the ignition coil then spark plugs. So, shops replace 6 spark plugs, 3 ignition coil, and removed cat, and replace with Megan test pipe (catalytic OEM cost too much). Three weeks later after running the car for about 1000 miles (car has 75,000 miles), 4 ignition coil burned, with noticeably burned on top portion of the coil. Anyone who might had this experience, pls let me know how you were able to fix this problem??

 

Welcome to our family and I wish I could help. My guess is you're having an electrical issue which might be hard to diagnose over the internet. I moved this thread to a place where it will get more views and maybe someone will read it and have a better answer than I do.

Good luck and if you ever figure out what the problem is please post it up here.

 

Make sure all the engine grounds are clean and tight.