I'm worried that this buildup might be the cause of my issue. Ever so often I'll go to downshift into 2nd attempt to rev match and nothing. The rpm's simply wont climb and the engine makes a noticable misfire sound. I've ordered new plugs in fear that they might be the issue but the current ones look clean. I haven't had time to pull the injectors to check for any gunk, but I'm going to switch over to my 93 map this weekend and run a tank or two of 93oct through the system. I'll report back in a week or 2 with my results.