I drove my evo to work, about an hour mostly highway. And when I got off the highway is when I noticed it. It would idle hang around 3k and drop to 2k. And bounce back and forth from 3k to 2k. At points holding at 3k. Found no vac leaks swapped out the iac valve tbs looks clean. Coils do smell a bit burnt not sure that would cause the problem though. Tuned on a 3 port with speed density e85. Any help would be appreciated

Evo 8