I posted over in the ignition section, but maybe i'll get more responces here, whats happening is at the track in 4th. gear ONLY (M6) at around 5000 rpm it coughed/popped back, it only does it once & only in 4th. gear, i'm sure its because its under the hardest load in 4th. (engine does feel alittle shacky in 4th. WOT), i was told it could be the ignition control module vs. Opti, it starts fine & runs fairly good otherwise under normal/moderate conditions, i'm hopeing its not the Opti, i haven't check if its throwing any codes, the SES light has been on ever sence i installed the LTs & Ory & eliminated the rear O2s. awhile back, how would you check the Ignition module? Has anyone exsperienced this before?

 

high rpm miss could be alot of things

plugs, wires, opti, coil, icm, etc

I believe shbox's website has a guide on how to test the icm http://www.shbox.com

pop the hood late at night and check for wires arching, if not then change the plugs

SES light could be from deleting the EGR or AIR