Driving around tonight, had some slight to moderate hesitation/stumbling under boost, anywhere above 3k RPM. Im guessing an ignition issue. Plugs are about 3 weeks old. My next guess is the leading coil?

 

Have you verified spark on the leading coil yet?

 

I have not, how can I go about doing this?

 

A frind of mine had the same problem starting about 5k. Turned out one of the posts on the leading coil was cracked under the plug wire boot and arcing to ground. Couldn't see it outside, noticed it as soon as we got it in the shop. Shows real pretty in the dark.