Misfire Diagnosis and Remedy Recommendation Request - 2009 9-3 with 2.8L V6

[isrosenberg]

I have a 2009 93 Aero XWD with a 6 speed manual transmission. I have owned the car since new. Just this last week it started misfiring in 6th gear with moderate to higher engine loads (accelerating at full boost).

It has the original calibration with no modifications and has never been "tuned". I always run 93 octane pump gasoline.

The current mileage is ~88,000 and the spark plugs were replaced as preventative maintenance at ~70,000 about 8 years ago. (This has become a second vehicle and doesn't accumulate many miles but it doesn't sit for long periods of time either.)

Before I throw a set of spark plugs and coils at this I wanted to see if anyone with more experience has a recommendation for further diagnosis as well as what brand/model plugs and coils to use with a standard calibration.

My current thoughts are to pull the front plugs and inspect them for condition and gap. Assuming nothing abnormal is observed I would leave the plugs and change out the cyl #6 coil or swap it with cyl 4 and see if the misfire moves with the coil.

I do have a BlueDriver OBD II reader and have some mode 6 data I'll try to attach (.jpg format) that indicates cyl 6 is the biggest contributor followed by cyl 2.

Any assistance is appreciated.