I'm blaze in Colorado. I have a 2000 Maxima 3.0L. The SES light is on with a code 1320. I changed the plugs and checked the ignition coils with an ohm meter. They checked okay, primary infinite and when the probes were reversed it was 2.1 to 2.3 ohms on each. The secondary was infinite. Any suggestions on what to check next? Also, I've read where all coils have been changed. Does this mean all were bad at the same time? Lastly, are laser platinum plugs okay for this car?