I posted earlier with this problem and some others responded but nobody ever reached any resolution. I now have new evidence. I spent much of the day riding around with the autotap running on the laptop after I did the plug change (64K-they didn't need it) and cleaning off the IAC pintle and port (it did.) Looking at the misfire history, misfires on the left bank (1,3,5,7) outnumber misfires on the right bank many times. It seems farfeched to blame the opiti or the coil for this one but all those wires are right there together and if the ignition wires are, indeed, failing, they could be failing together. At 60K it could be wires. The underhood temperatures are high in these cars and this is Texas, after all. Anybody else notice this?

 

I had the same code before. It's basically either going to be your Opti going out, cracked spark plugs, Miss routed wires, or bad wires. The coil can cause it also. But I would first Check to make sure you connected the wire right first. Next check the plugs, sometimes if you dont tighten them good, they back out and cause your problem. You can take your Coil in to get tested at AutoZone or Advanced. Then if everything else is good, then its your Opti. Hopefully this helps yeah. This code is just a process of elimination.