[Electron Man]

There are connectors used to transmit the spark signal from coil pack to each plug. If they are still the originals (~18yrs old or more), try replacing the two that look the worst.

These can get flaky when they heat up if they're old.

Also, go through the wiring harness (ECU - ICM and ICM - coils) to look for cracked insulation.

 

[Electron Man]

Maybe the AUG and AWM 1,8T's are demanding, but the AEB will run fine on just about any plug of the proper heat range (engine tune dependent) with a solid copper center electrode (gapped to 0.028"). Find some Bosch F6DTCs (a 3 electrode plug) as a starting point. I ran these for 5 yrs (changed every 20K) with no misfire problems.